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When installing or upgrading to the latest version of Windows, one of the first decisions is 32-bit or 64-bit? I'll look at which you should choose.

Recently, I switched from XP to Windows 7. During loading it asked me if I wanted 32-bit or 64-bit. I think I made a mistake when I requested 32bit. I wasn't sure if my machine was 32-bit or 64-bit. How would I know? I built this machine about two years ago. Is there any way to change it to 64-bit?

Which do I want?

32 versus 64 has a number of people confused - it's a question I get often. In fact, it's probably the most common "in person" question I get from friends and acquaintances.

I won't spend too much time on the actual differences between the two, but focus instead on the two key issues:

Will your machine even support 64-bit processing, and if it does, do you want it?

A minimal refresher:

A "bit" is an entity that can have a value of either 0 or 1, that's all. And that's all that computers know how to work on. Everything is all about bits. Thinking of them in groups makes it easier for humans to think about it. As a result we have things like a byte being 8 bits, having a value in the range 0 to 255.

"There's no easy 'upgrade' or way to switch from one version to the other in place."

Computers, like humans, also work on bits in groups - typically in groups of 8, 16, 32 or 64 bits. Computers do this not to make their "understanding" of the bits any easier, but rather for a different reason entirely: speed. A 32 bit processor works on information 32 bits at a time (grossly oversimplifying here, but that's the concept anyway), and a 64 bit processor works on it 64 bits at a time. The difference is in hardware - typically all the way from the CPU itself to the memory installed on your machine and their interconnections on the motherboard.

So, how do you know what your machine is capable of?

The quickest and easiest way I know of is to grab a free copy of SecureAble. Run it and it'll tell you in pretty clear terms what you have:

Securable displaying processor capabilities

If it says 32, your decision has been made for you. You can only run the 32 bit version of Windows.

So, what if it says "64"?

I've updated my position to be a bit stronger than it has been in the past. At this point I would actually suggest installing the 64-bit version of Windows - particularly if you're looking at Windows 7.

There are two exceptions where I would still at least consider installing the 32-bit version:

  • If your machine will never have or is incapable of having 4 gigabytes of RAM or more. For example, if the machine has 3 gigabytes of RAM and will never have more, then one of 64-bit Windows major advantages goes away. On the other hand, if you have 4 gigabytes or more, then 64-bit is probably the way to go.

  • If you know of compatibility issues with applications that you need to run. Now, I do have to say after having run 64-bit Windows 7, I've encountered zero 64-bit related issues. None. And even then, were I to run into a problem I'd investigate alternatives, like running a 32-bit operating system in a virtual machine.

Conversely, if your machine has more than 4 gigabytes of memory, then the decision is also pretty clear: 64-bit Windows is the only version of Windows that will take advantage of all that extra RAM. If your 64-bit machine is capable of having more than 4 gigabytes of memory even though it may not have it right now you may also want to consider the 64-bit version of Windows anyway, so as to automatically take advantage of that RAM when it's installed.

The Pain of Switching

Unfortunately, it's pretty important to think through the decision up front.

Switching between 32-bit and 64-bit is a pain.

How much of a pain?

It's a "backup, reformat and reinstall Windows" kind of pain. There's no easy "upgrade" or way to switch from one version to the other in place.

When in doubt, if you're still not sure, then run SecureAble and install whichever version of Windows it tells you you're machine is capable of. That will work just great for almost all common situations. Spend some time confirming that things like printers and other devices work, and if not you can revert to 32-bit with a reinstall if you need to before you've gone too far.

Article C4255 - April 2, 2010 « »

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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?

April 2, 2010 1:38 PM

Does this really answer the question?
It seems to be a skirt around.

Mr On Line
April 3, 2010 4:41 AM

that is very enlightening .. really .
but can i install 32 bit applications on 64 bit application and what is the difference would be exactly ??
i found out that my machine can run the 64 bit version but why do i need it ?? is it faster ?

Thanks :)

Almost all 32 bit applications work just fine in 64 bits. Technicaly 64 bits might be a tad faster, but the big reason today os to take advantage of the higher memory capacities of modern machines.

Ken Laninga
April 6, 2010 8:22 AM

I had planned to get a 32-bit machine next time I needed a new 'puter. Then my Acer died and I had to rush out an buy something new. Liked the Asus and the salesman told me it was BOTH 32 and 64 and I'd have no problem running all my old 32-bit programs. He was correct. NO problem. Don't even notice the difference. The ONLY thing I notice is that there are TWO "Program files" folders in C now; one is "Program files (x86)."

Glenn Capone
April 6, 2010 8:31 AM

The only application I've found that I can't install on a Windows 7 machine (mine is a Compaq with 64 bit Win 7 pre installed) is the desktop for my Palm organizer. I know; that is soooo old school, but I really like the thing.

No help from Palm either, they don't look like they are going to write a new desktop to sync with anytime soon(or ever), and there doesn't seem to be a work around from Microsoft. I guess I have to keep my old Windows 98 laptop going to sync with...

You might look into Windows XP mode: What is Windows 7's "Windows XP Mode"? (And can I use it to get Outlook Express back?) - you can run 32 bit XP within 64 bit Windwos 7.

Bob Fisher
April 6, 2010 8:33 AM

I have both Windows 7 32 and 64 bit versions installed on my computers. I find that the 64 bit version is not as stable; there are Internet Explorer problems and finally my old printer, which works fine, does not have 64 bit drivers

April 6, 2010 8:48 AM

I have the 64-bit version of W7 installed on my comp. and it generally presents no problems. I normally use the Chrome browser because of its speed and the two work well together. However, I have found that for occasional on-line transactions (e.g. on-line banking) I have to switch from Chrome to IE to do the deal. Dunno if this is related to the browser or the OS.

Dave Jones
April 6, 2010 9:13 AM

The problem is compatability. If you are going to use your computer for large files like editing video, then yes to 64 bit, but for home use, 32 bit is going to give you a better chance of compatibility for hardware, software, and drivers. Amazing how many vendors will not write a driver for 64bit. Using xp compatibilty for software is one thing, but you better make sure that printer has a 64 bit driver, or try pluggin in that old scanner, or other misc hardware you may have used with XP. I dual boot from XP pro 32 bit and Vista 64 Ultimate and spend most of my time in XP because I do dot want to spend the money to buy a new printer or upgrade all my software. The printer companies are happy to sell you a new printer and give you a $10 trade in. Microsoft has a compatibility site. Learn to use it. I just ordered a new printer for someone yesterday because C****** had no 64 bit drivers for a older laser printer.

Judy Olson
April 6, 2010 10:14 AM

We bought a new laptop and discovered after receiving the 'recommended by the dealer' 64 bit version that Adobe Flash doesn't have a driver yet. Therefore, we're having to use the 32 bit version of Internet Explorer on it in order to view any flash media. Wouldn't you think?????????????

April 6, 2010 12:22 PM

I just bought windows 7 32 bit. A friend told me it was 32, but when I took to shop the tech told me to look on side of my computer and there in black and white says 64 bit. I just hope I havent made big mistake by puttin in the 32. I just got it back and so far no problems with the 32 bit

April 6, 2010 12:32 PM

@judy: 64 bit applications tend to be of less use, unless its something like an intensive video editing program that can use the extra memory or an accounting program that can use the precision. I personally have had one issue with 64 bit, but today's CPU's are so powerful, and machines running 64 bit OS's have so much RAM, that it is perfectly possible to virtualize another OS.

April 6, 2010 2:20 PM

I just bought a new computer at a pretty good deal, and it's a dual-core with 64-bit processing, along with 6 Gb of RAM. For what I paid, it does exactly what I'd expect, run my 32-bit programs just fine, which is all that I have. In other words, half of my computer is unused.

If you've spent hundreds, or thousands, of dollars on your industrial-strength programs, 64-bit computing is necessary, but for most consumer applications, it offers little improvement to make it worth the cost or effort. Like owning a car that can do 200 mph, when most speed limits never exceed 70.

Even gamers are still complaining. All the cores and bits in the world won't make up for poor code writing in the programs.

Renate Gieseke
April 13, 2010 10:00 AM

Can I install a kind of virtual XP under WIN 7 (64 bit) to have old software running, like my COLLINS ENGLISH GERMAN DICTIONARY? A friend warned me, that if I do that I would put my computer at risk for all kinds of worms, trojans, etc. etc. Is that so???

That's exactly what Windows XP Mode is, and is for. It doesn't open you to additional risk.
September 7, 2010 11:34 AM

Here is my input on Windows 7 64 bit vs. Windows 7 32 bit. About a year and a half ago I built a new computer and decided to install Vista 64-bit software for Windows. Everything went fine except I did not find very many 64-bit programs and those that I found it said would worked with 64-bit operating systems did not seem to work as well as they did in 32-bit. When Windows 7 came along I got the package that had both 32-bit and 64-bit versions. I decided to go with a new install again of the 64-bit Windows 7. Again the same 32-bit programs did not work that fast for me in 64-bit. So after a lot of frustration I uninstalled the 64-bit operating system and used the 32-bit disk. As of today everything is working great. In my opinion 64-bit is the future but the future is not here yet. 32-bit is still king until the software companies start writing true 64-bit software. 32-bit will be what I will stick with for now. If you run Windows 7, the 64-bit version it will create a directory called SysWoW64. When you install a 32-bit program it somehow uses that directory to tell Windows to emulate a 64-bit program even though it is 32-bit. In the 32-bit system you will normally install all of your programs in a directory labeled Program Files. Well, in the 64-bit system you will have two directories. If you install a true 64-bit program, it will be install in a directory labeled as Program Files. If it is a 32-bit program it will be installed in a program labeled as Program Files (x86).
For those concerned about the 3.5 GB limitation on 32-bit operating systems, I suggest you read the following websites. The first one is and the second one is After reading those 2 websites you will find that you can use more than 3.5 gigs of memory and a 32-bit operating system I currently have 12 gigs of memory in my 32-bit Windows 7 system, and everything works fine. All the programs work fine because they are 32-bit programs.

Just to give you an example of what I am talking about, one of the programs that I ran was Dragon NaturallySpeaking version 10.
Nuance came out with a patch that made their program compatible with 64-bit operating systems. Yes it worked but to me it seemed to work very slow. Now I am running the same program on my 32-bit Windows 7 and it works great.

I hope this explanation helps anyone trying to decide if they want to run 32-bit or 64-bit operating system.

November 5, 2010 1:47 PM

I built a pc and installed win7 64-bit... no problems except for one big one which shows up nearly every day: adobe flash will not run on 64-bit yet, so no youtube, no video, no etc. Got to use Chrome or another to see those. What a pain.... I'd install 32-bit next time.. yeh, the future ain't here yet.

You don't need to install 32 bit to see videos. IE is provided in both 32bit and 64bit versions with Windows. Use the 32 bit version and videos'll work just fine. Or, as I do, run FireFox.

Matt M
December 16, 2010 12:21 PM

Upgraded to Windows 7 64 bit recently and it's been a disaster. Neither IE 32 bit nor Firefox work (they both just lock up on starting), and of course Flash doesn't work in 64 bit IE, making 64 bit IE basically useless.

Going to suck it up and reinstall 32 bit win 7.

For the record, there's something else going on here. 32bit Firefox and IE, as well as Flash in those browsers, works just fine on every 64bit Windows 7 system I've run.

Geoff Walker
July 12, 2011 4:27 PM


You say that "[You've] updated [your] position [on 64-bit Windows] to be a bit (pun?) stronger than it has been in the past". That's good, but the positions you've taken in the past are still online in related items published in 2007 through 2010. I'm curious how you deal with this "revisionist history" issue. Should you go back and update the old items on 32-bit vs. 64-bit Windows with your new position? There must be dozens if not hundreds of topics like this one where your opinion changes over time as more information and experience becomes available. It seems impractical to update them all, but is this one important enough to make it worthwhile?

In any case, thank you for clearly explaining the whole 32-bit vs. 64-bit issue. I hadn't fully understood all the aspects of it before.

FYI, I recently configured and loaded a friend's new 64-bit Dell that came with 64-bit Windows-7. Of the 50+ apps that I installed, I only found two or three (games from the 1990s) that wouldn't install due to an "incompatible with 64-bit" message. I also found that installing very old apps first on a system running 32-bit Windows-7 and then copying the program files over to the 64-bit system allowed some of them to run.

January 27, 2012 9:25 AM

Joe - not everyone can follow that guides as you addressed. If the motherboard chipset cannot support memory remapping and there is no memory remapping feature in the BIOS then there is no way at all (even with PAE patch applied and 64-bit OS installed).

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