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You can move the I386 folder, but in order to keep Windows File Protection happy, you'll need to update a registry key as well.

The folder c:\i386 takes up a lot of space on my hard disk, so I moved it to a drive on another machine on my network where I have more room. I'm now getting Windows File Protection errors, and there's no option to tell it where the files are. What do I do?

I actually get variations of this question on a regular basis. Recently as I was cleaning up the hard disk on my primary machine I found myself asking the same question.

The answer is that you can move I386, if you then also make another change deep in the Windows registry.

If it exists C:\I386 (the folder "I386" at the root of your "C:" drive) most likely contains an image of the installation copy of Windows. It's often placed on your hard drive as a way to avoid having to ask for a CD when Windows decides it needs some file that hasn't yet been installed.

It's also used as one of the repositories for the original files used by System File Protection and the System File Checker. If Windows determines that one of its files has been replaced with an unrecognized copy, perhaps due to a virus, then the System File Checker will restore the file to its original version from C:\I386. (It actually uses additional repositories as well, in case service packs and other updates have legitimately updated the file.)

In an attempt to answer the question "I wonder what happens if ...", I carefully backed up the contents of my C:\I386 folder, and then deleted it.

The next morning I woke up to this error message:

Windows File Protection Error

".. you can move your I386 folder to wherever you like, as long as it remains visible to your machine, and you make the registry update to let Windows know where it is."

Windows File Protection had attempted to check my system files. I'm fairly certain that the error message it technically incorrect. No files had been replaced by unrecognized versions. Rather, the error was simply that the reference copy it expected in C:\I386 was no longer there.

I restored the copy of my machine's C:\I386 folder to another machine, on a folder that had been shared and that was visible on my local network.

The "trick" to telling Windows where to look turns out to be a simple registry setting. Specifically the key HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Setup\SourcePath.

Firing up regedit, locate that key:

Registry Editor opened on the SourcePath setting

Note how it's set to "C:\" by default. The folder must be named I386, and this setting tells Windows where to find that folder. Double clicking on SourcePath, you can then change it to be the full path to the I386 folder:

Editting the SourcePath value

Note that it doesn't include the "I386", it just points to where I386 can be found. In my case it's \\freenas\notenmax\machine_specific\leo\i386, but the registry setting is \\freenas\notenmax\machine_specific\leo. (In my case "freenas" is the server, "notenmax" is the share, and then "machine_specific" and "leo" are just folders within that share. I386 does not have to be at the root of the share.)

Once updated, the setting does not take effect until you reboot.

After rebooting I opened up a command prompt window and forced Windows File Protection to check all my files by running the System File Checker (SFC /scannow):

Window File Checker progress

It completed normally, indicating that all files were good, and that the I386 folder had been accessed successfully from its new location.

The bottom line: you can move your I386 folder to wherever you like, as long as it remains visible to your machine and you make the registry update to let Windows know where it is.

Article C3104 - August 2, 2007 « »

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Leo Leo A. Notenboom has been playing with computers since he was required to take a programming class in 1976. An 18 year career as a programmer at Microsoft soon followed. After "retiring" in 2001, Leo started Ask Leo! in 2003 as a place for answers to common computer and technical questions. More about Leo.

Not what you needed?

David Goulding
August 4, 2007 12:16 AM

After reading the article, I checked my Registry to find that although the I386 folder is definitely located on the C:\ drive, the SourcePath is recorded as F:\, which is my DVD drive! I don't experience any errors, so should I edit this to read C:\ or leave well alone?

August 4, 2007 2:56 AM

thank you for solution about ur i386 suject

Leo A. Notenboom
August 5, 2007 8:17 AM

Hash: SHA1


My general philosophy is "if it ain't broke, don't fix it". :-)

But you point out something I overlooked in the article: the SourcePath can
often be pointed a the CD or DVD drive, and hence requires you to insert the CD
or DVD on which you have Windows. Pointing it at C:\I386, **if it's the same
as on your CD** is a convenience to avoid having to load the CD when it's

But I'd leave it alone until or unless it became a nuisance.


Version: GnuPG v1.4.7 (MingW32)


August 17, 2007 4:50 PM

The new Secunia Personal Software Inspector ( is a program that looks for old versions of programs that have been superceded and contain holes that can be exploited by virii or malware. It reports old versions with known holes in my i386 folder (such as an old Flash player). I know that I'm not running these versions from i386 on a routine basis, but I would like to delete them to prevent them from being loaded in the future, or prevent the module from being loaded by a malevalent program. However, removing them (assuming that I could find them among the compressed files in i386) might cause errors that could prevent Windows from using other information in the i386 folder. Any advice?

Leo A. Notenboom
August 19, 2007 12:51 PM

Hash: SHA1

I would leave the contents of the I386 folder alone. It represents a snapshot
of the I386 folder from your install CD. If things are updated, they'll be
reflected in other directories (like the SP2 related I386) elsewhere on your
machine. I would expect modifying the contents of I386 to have unpredictable


Version: GnuPG v1.4.7 (MingW32)


Amit, NYC, NY
December 15, 2007 1:35 PM

Thanks for the info. This will help me tremendously. Thanks again.

Karen James
January 10, 2008 3:32 AM

I can not find the Source Path on my Registry Editor, now what do I do. I am having the same problem mentioned here with not having desktop icons, task bar or startup menu. I hope you can help me.

Karen James
January 11, 2008 11:41 PM

Ok, I have found out that my sourcepath was pointed at my e drive which is my DVD burner/player. I changed it to my C: drive but not sure what else I need to do. I see in your example you have \\freenas\notemax\machine_specific\leo. How do I find out what my server and share are?

Leo A. Notenboom
January 13, 2008 12:25 PM

Hash: SHA1

The location you specify is wherever you copied the I386
folder of your installation CD.


Version: GnuPG v1.4.7 (MingW32)


PC Resolver
January 14, 2008 1:40 AM

I changed the sourcepath but it didn't work. I had to change ServicePackSource and Installation Sources. I changed them both at the same time so you may get by just changing one of them.

John Federhofer
February 9, 2008 4:32 AM

I cannot locate the I386 directory on my root C drive.

I reformatted my drive after a system crash and reinstalled windows and all software. But there is not I386 in the C root.

I tried sfc/scannow, but it won't run.

Anything I can/should do?

Jack Federhofer

February 12, 2008 11:38 AM

I'm having problems with Explorer crashing about once a day. It happens at different times while running different programs. I want to use sfc/scannow but as I own a Gateway I only have a Recovery Disk not an actual Xp disk which scannow doesn't understand and won't use as is. How do I replace my (as yet unknown) corrupt system files using the disk I have and scannow? Is there another option short of the dreaded reinstall?

Craig Davidson
March 22, 2008 11:40 AM

I've moved my I386 file from my C drive to my E drive (my second hard drive). Now whenever I try to copy the I386 file to a dvd, it won't let me. I haven't deleted the file from my C drive yet (basically I have an I386 on both my C and E drives), and neither will copy to a dvd. I get the message "Windows has encountered a problem when trying to copy this folder. What do you want Windows to do?" -Retry- -Skip- -Cancel- I don't want to delete it from my C drive until I have a physical copy, in case there was a problem. What can I do?

Kim Fox
May 23, 2008 12:20 PM


But it appears a reboot isn't necessary, once the registry entry has been changed.

After editing my registry, I immediately called "sfc /scannow" and it began running properly.

Mark S
June 8, 2008 7:48 AM

I have a somewhat related problem. I inserted a card into a hub/combo card reader and windows crashed and then rebooted. Since then, all my USB devices have been acting erratically. I've tested them with another computer and they work fine. My guess: some files were corrupted in the crash. I got the "Files that are required to run..." Windows properly error box that you reference above. However, it demands an XP Professional SP2 CD rom. I upgraded to SP2 over the web. I have no CD rom to give it. It doesn't care about my original windows Home disk.

I ran the system file checker and it too asked me to insert the SP2 Pro disk I don't have. So apparently there are some files that need to be fixed or replaced. But I have no way to do this.

Any tips, other than buying another copy of Windows? Thanks in advance.

August 4, 2008 7:30 AM

I need to run sfc on a second hard drive installed in my system. The dribe is labeled f:. Is it possible to run sfc on the F drive?

SFC doesn't run "on a drive", it runs on your system. That means it checks the Windows installation in use wherevere it might have been installed.


John Jenkins
September 5, 2008 5:31 PM

Another web "author" that doesn't take the time to develop the site correctly. I went to print these instructions out and the right margin was clipped...can't do it right just get out of the business.

Yeah, I know I'm pretty clueless on this whole web/computer/printing thing. I mean doing it for only 30 years means I'm pretty much a newless cluebie, right? :-)

Perhaps what you're seeing is that the right navbar/column is intentionally not printed since you can't click links on paper. Ads are also not printed. I've spend some time crafting the print experience on the site. It ain't perfect, but its good.

If you're actually seeing clipping, then: Why is only the left hand part of my page printed?


Jonathan Eccles
October 10, 2008 8:34 AM

I am running WindowsXP Sp2 and am getting the error reported at the head of the page under "Windws File protestion" having moved c:\i386 to c:\windows and having altered the registry as instructed. What is being done wrong?
Kind regards, Jon

Gloria Elliott
October 11, 2008 2:57 PM

I followed the link you provided all the way to Setup, there is no Source Path. What do I do now?

I'm trying to let Windows know where i386 is so SFC won't keep asking for the CD.

October 29, 2008 9:28 PM

How can I recover Regedit if it was omitted from Windows Installer? I really need this one Thanks

December 6, 2008 7:20 AM

Hi Leo
I followed the instructions above as my SR has simply dissappeared!
When i do the HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Setup\SourcePath. search I find my "source path" is shown as D:\ when, having searched, it (I386 folder) is actually in C:\ I have no idea why the discrepancy as I certianly didn't move it!

My question is, in order to fix my problem do I simply change the source path back to C:\ (as per instructions above) and then reboot and run SFC/SCANNOW?
I hope so because other wise I'm lost!

A few details missing from what you've posted, so I can't be 100% certain, but sure - shouldn't hurt to try.
- Leo
December 7, 2008 2:48 AM

I have tried everything here and nothing seem to work because I am still prompted to insert the CD even after rebooting and double checking my entries in registry
questions does it matter if there is 2 partitions on my drive
and is there a log file anywhere where I can see the progress to see if it is directed at the right spot in the sequence

December 8, 2008 6:54 AM

Hi Leo,
I changed the source path back to C:\ but get the same result when running sfc/scannow. ie it tells me to insert my xp disc!!
Now I'm lost, still without system restore and frightened to do anything on my PC untill I have SR restored to it's proper self! Any ideas please?

December 9, 2008 6:32 AM

Failing that is there somewhere I can download "system restore" from and just re-install it on my PC?

December 9, 2008 7:38 AM

Hi Leo,
found this article on my travels and it worked for me. Hope it will help others in the same boat.
If posting this link here is out of order I'm sure you will delete it and I apologise but as I say it worked for me and my SR is now working again.

December 15, 2008 8:55 PM

Simply changing SourcePath isn't sufficient if SP2 is installed. I had to change ServicePackSourcePath as well. HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SourcePath may also need to be changed, but I'm not sure (I changed them all at the same time).

January 5, 2009 5:12 AM

I was trying this today and initially failed because I didn't know that it was necessary when editing the registry to put file paths in inverted commas whenever a space is present. I had copied my I386 directory to C:\Win2kP setups and the space had prevented the registry change from being effective; I then found in a blog on this subject
that I should have written "C:\Win2kP setups" .

Now SFC works properly. So either don't use a file or folder name with a space or put the path in inverted commas.

I hope this helps someone.

Daddy Dude
January 13, 2009 8:21 PM

I found I was gettign that error also after i got Trojan downloader virus. It rewrote my reg source path to D so I could not get on and kept getting that anoying message. I renamed the path to C and all is working fine again. thanks to finding this page! not for the reason he said but knowing Path should be C by default was a great help.

Mike Anderson
July 19, 2009 9:04 PM

I just wanted to thank you for the info included in this post. I followed your instructions to the letter, and freed up some very much needed space on my system partition. Thank you!

G Birch
November 28, 2009 2:04 PM

If I have the I386 file folder from an IBM T42 can I use it with a Sony VaioFE31-H, as I have no CD or I386 file for the Sony. If so, should I copy and paste it into my Sony C: drive

I'd be shocked if it worked. See this article, the basics are the same: Can I install Windows XP using one manufacturer's CD on a different pc?

Jamey Odau
February 5, 2010 11:45 AM

kernal32.dll is missing to run a pdf how do i correct this/

Alison Murney
September 17, 2010 7:19 PM

Hi Leo - My registry does not have the folder SourcePath. What should I do - can I just create a folder in the registry with this name?

November 19, 2010 6:28 AM

when using regedit to find HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Setup\SourcePath. my reg editir states that source path is looking at D:\ is this right? I've had a few problems with the PC as i had two trogans and they were removed by malwarebytes but if this source path is wrong then changing it to C:\ might solve my other problems - IE no longer works at all

It's not uncommon for I386 to be on D:. It's location has nothing to do with whether running programs work or not - it's only used at the time of installing programs or features in Windows.

D wazzle
September 23, 2011 1:10 AM

Im running xp pro sp3, Ive tried changing that registry location to my I386 folder(correctly) but sfc still demands the cd. why?

another problem lately, is when i run sfc /scannow it doesnt replace any of the files it finds is corrupted. Sfc used to run and each time it found a file it said "retry". when it would finish and i would run it again it no longer came up with the "retry" so I knew it had replaced them. Now it just shows the same retry demands as it did the 1st time and I can tell that the Op system is slowly getting more corrupted. why is it no longer replacing files? is there a public software that can replace sfc?

The only alterantive I'm aware of to SFC is to re-install the operating system. If your OS is becoming more and more corrupt, I would do that, and then also figure out WHY it's becoming more and more corrupt and take steps to stop that from happening - it shouldn't.

November 28, 2011 11:39 AM

Dear Leo,

I knew 'SFC / scannow' allready by a moderator who helped me. I have the problem too of a pop-up that asks me a cd of XP with SP3 for all the dll's. I have burned a cd with the iso of SP3, also I have tried several other things...till I formatted my HD and installed it allover, a new install....the 1st thing is that I did 'SFC / scannow', on the installment of how i bought the pc brand new in the shop....there was the same question about the cd! Was it corrupt when I bought it?
The weird thing is, my sister, my father, and brother of my sisters husband all have the same pc, and with all the 'SFC / scannow' isn't working and there is asked for a cd of XP for SP3 to load all the dll's...
On Microsoft is nothing to find yet that helped...
I know XP is old and antique in the world of pc's, maybe that's the crucial factor. Though i like XP...
Do you recognise the problem? I read somewhere about the i386, that's a part of SP3 too, that it has a shadow file somewhere...when rebooting, it wouldn't be the same in both files, the shadow file is recovering to the previous status, so they are not the same, that would cause this? I couldn't find the page anymore where i read it unfortunately.
Thank you for you site with info&suggestions, i like it.
Best regards.

Willy Haile
July 4, 2012 4:48 PM

I can't find sfc on my windows xp...I take it it comes in a store bought CD?? I have corrupt videos from a Flip camcorder...will only play if I scroll down menu on the file to "Play on my 'Acer x193w' " otherwise defaults to first one played

Tony Kightley
October 17, 2012 2:51 AM

Having read your article about telling Windows where to find the I386 folder, I did not remember seeing I386 in the C:\ directory on my Laptop, so I checked and, then, did a search. I found 50 folders entitled I386 or i386, varying from a few Kb to 113Mb! Most were associated with ParetoLogic Anti Virus, apparently, and were in the Docs. & Settings\All Users\App. Data\etc. Directory. As I do have a CD for the Win XP OS on the Laptop, the fact that an I386 folder is not in C:\ should not be a problem. Is it normal or common for proprietary programs to use i386 folders?
However, what did puzzle me was several i386 folders in the a C/Windows directory such as Driver Cache and ServicePackFiles, although the corresponding C:\Windows folders were, also, present. These rouge folders were, all, dated May 2011 and contained 0kb of data, so what I did to get them is a mystery - unless you have any ideas! I did manage to delete them.

Mark J
October 17, 2012 11:25 AM

None of the things you mentioned is of any particular concern, unless you are having other problems with your computer. It's not unusual for a proprietary program or driver to have a /i386 folder. i386 is sometimes used as a designation for 32 bit applications or drivers to distinguish it from x64 drivers which are 64 bit apps or drivers. I386 refers to the Intel 386 (or 80386) processor, the first 32 bit processor. The i386 processor hasn't been produces in the last 18 years, but the i386 designation is used to refer to all 32 bit processors

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