Helping people with computers... one answer at a time.

It's something we take for granted, but copying files from PC to PC is one avenue for malware to spread. I'll review the best way to stay safe.

I just bought a new PC. I want to transfer (download?) files from the old PC I am using to write this eMail to the new one. However,I'm afraid I may inadvertently be transferring malware as well. My present OS is Windows XP. I have 2 anti-malware programs installed on the old PC: AdAware and Reimage. My question - can I download files from the old PC onto CD's and then safely upload the data to the new PC? I believe my question is worth posting as the answer may help other novices like me.

Once again, I get to haul out my most common answer: it depends.

In general moving files from machine to machine is essentially what computers are all about, so certainly it must be safe to do so.

The trick, of course, is knowing how do it safely. I think you're on the right track, but I want to clarify the scenario a little and correct a little terminology along the way as well.

Uploads, Downloads and Copying

In general upload/download is the wrong terminology if you're talking about computers in front of you. We generally think of uploading or downloading from computers that are "far away" - like downloading updates, software, email, photographs and such from servers on the internet.

"Of course the real trick to not accidentally copying malware is to not have it in the first place."

When we're talking about your computer and a CD that you might create, you're just copying files. You make a copy on the CD or copy it to the CD, and then when the disc is inserted into the other machine copy the file to that PC.

It's not an absolute, by any means, but conceptually a download feels like its more difficult or feels like it should take longer since it might be happening over a slower connection than a copy to something like a CD or locally networked computer.

It's true that there are always exceptions to the rules - and these aren't even rules. (Some people "download" files to a USB thumbdrive, I "copy".) But for what you've described, most folks would say you're copying files around.

Copying Safely

Regardless of what you call it, moving files around is certainly one way that malware spreads.

The basic approach you're taking is a good one, but...

You haven't said exactly what files you're copying.

In general, data files are less likely to contain malware than programs. So if you're just copying, say, pictures around, or documents, you're at much less risk than if you're copying program (.exe, .dll) files.

Another thing to look at is where did the files come from? If they're files that you created then once again the chances of malware are lower than if they're files you downloaded from the internet or received from other sources. Similarly even if they are downloaded programs, (one of the more common sources of malware), did you get it from a place you trust?

None of these are absolutes rule, just things to consider as you move things around.

Try and at least understand what it is you're copying around and where it came from originally, and that'll help you understand the level of concern that might be warranted.

Antimalware Software

Of course the real trick to not accidentally copying malware is to not have it in the first place.

That means going back to the fundamentals on your old machine: good anti-virus protection, good anti-spyware protection, a firewall, and of course common sense.

I can't comment on that last attribute, and you didn't mention whether you have a firewall, but the anti-malware tools you have concern me just a little.

AdAware is an anti-spyware tool. Reimage isn't an anti-malware tool at all - it's a PC repair tool.

If I understand you correctly that leaves you with no anti-virus protection at all.

Before you copy files ... get some.

I have recommendations of course, but more important than my specific recommendation is that you review exactly what it takes to stay safe on the internet.

If you can be reasonably certain that your original older machine is relatively clean of malware and threats, then you're in a position to not worry as much and copy what you like in reasonable safety.

Article C4692 - December 29, 2010 « »

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?

Bernard Martin
January 4, 2011 9:47 AM

... but is there an easier way than copying to disks and recopying to the new machine? Can't I just plug the old machine into the new one and copy stuff across? Especially programmes (like Filemaker, Quicken) that are licensed to just one, specific machine. If I can... how?
Great site, by the way!!!

You can copy data files, but programs need to be installed - i.e. the setup program needs to be run on the new machine. There are utilities that claim to be able to transfer software from machine to machine, but they tend to be pricey, and I much prefer (and recommend) performing a clean install.

Alex Dow
January 4, 2011 11:27 AM

Before doing any Copying to CDs, DVDS or by cable/WiFi connections to another PC, do as Leo has said, make sure you have proper protection on the old PC; and separately/independently on the new PC.

Run the Anti-Viral Program to cover all the nooks and crannies on the old PC.

Also download Microsoft's Malicious Software Removal Tool to the old PC and again fully check trhat old PC.

Totally separately download directly from the Web, the same AV and MSR software to the "new" PC - AND carry out similar tests on it.

Alternatively use any AV program supplied with the new PC.

That way, you can be "reasonably" sure that both PCs are clean, before tranferring any files from old to new.


Then remove any unwanted files, directories etc - BUT be wary!


Regardiing the transfer method, I would suggest that you get an external HDD as large or larger than the internal HDD on the new PC.

Connect that eHDD to the old PC and do a FULL Backup from the old PC to the eHDD.

Then connect the eHDD to the new PC, doing a FULL RESTORE from the eHDD Backup to the new PC.

Generally this will be much faster than using CDs, DVDs etc - AND you will have gained an eHDD for future Backups of your new PC.

All those actions will give you a more secure and safer system.


There are other ways such as LAPLINK - but it is many years since I used that, so I don't know how the present version performs.

Alex Dow

January 5, 2011 2:16 AM

A friend of mine took the hard drive out of his old computer then hooked it to where the cd-rom goes in the new one booted it up and was able to copy the files straight from the hard drive to the new computer i would'nt recommend doing it but it did work for him

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