Reader: Windows says my software's counterfeit. What to do?

Reader Ann writes: My PC was infected with a virus just a month ago. I have deleted the virus and none are now showing up in scans. Then, about a week ago, a message popped up stating that there is new version of Internet Explorer, asking me whether I wanted to update. I clicked yes. Now, every time i switch on the PC there is a message telling me that "You may be a victim of software counterfeiting." Is this another virus or what?

The good news, Ann, is that it's not a virus. The bad news is that it's actually going to be harder to get rid of that message than if it was.

What has almost surely happened here is that you have been caught up in the anti-piracy dragnet of Windows Genuine Advantage, the much-hated Big Brother program that's part of all XP and Vista machines now. WGA, which I've written about extensively in the past, essentially checks your Windows license key against a database of keys at Microsoft headquarters. If your key is marked as counterfeit (the database is updated constantly with new keys), you get that popup.

In XP, WGA is mainly just a nuisance. If you were running Vista, the impact can be considerably more troublesome.

Solutions? First is to make sure you don't actually have a pirated copy of Windows. Where did your operating system software come from? Preinstalled on your PC or did you install it yourself? Do you have any documentation of the serial number, especially the original disc and packaging? This will be very helpful if you've determined that your copy of Windows is legitimate.

If you believe your system to be non-counterfeit (and, by some estimates, over 90 percent of WGA counterfeit notices are false positives), your next step is to run some additional tools to try to troubleshoot WGA. There's another tool called MGA Diagnostic that might be able to help. Microsoft has a detailed post here on how to run MGA Diagnostic. Start here (choose "Resolve Now") then download and run the MGA Diagnostic tool here. Copy the results and paste them on the WGA forums above and/or on the Windows Update forum here for analysis by Microsoft. Most questions are answered within a few hours. If you want to bypass all of that you should see a toll-free number you can use to call Microsoft support to directly discuss a fix (click "Get Genuine"), but chances are you'll just be pushed into buying a new copy of Windows.

If you've discovered your software is indeed counterfeit, you'll need to pony up and buy a new copy, or just suffer with the WGA notifications. If you buy a new copy, you can use these instructions to change the key, which should then pass WGA inspection and no longer slam you with pop-up messages. Good luck.

See also: WGA FAQ