AVG bug leaves Windows unbootable

Another day, another bug in an anti-virus product: this time it's AVG's turn to cause some heartache the world over.

CNet has announced that Grisoft's AVG 8 anti-virus product received an update on Tuesday which caused it to detect an important Windows system file as a virus, giving users an option to delete the file – and hose their systems.

Affecting users of AVG 8 on Dutch, French, Italian, Portuguese, and Spanish editions of Windows XP – both Home and Professional – the bug causes AVG to detect user32.dll as a Trojan horse, leaving users open to the possibility of deleting or quarantining a file which Windows requires for continued operation.

The company has issued a statement saying that it is "actively working to remedy the problem some users are experiencing related to the most recent update to commercial and free versions of AVG 7.5 and AVG 8.0 in some languages." As of last night, a bootable CD image was released which is designed to repair a system that has been rendered unbootable by the bug – although you'll need a second computer to burn the CD on, obviously – along with a new virus definition update which removes the false positive. For users that don't have a second machine on which to download the fix, Grisoft recommends that they "contact their AVG reseller or ask a friend to download the information and fix tool for them."

Is this evidence that the entire concept of a signature-based anti-virus package is flawed, or does Grisoft just need to improve their QA testing procedures? Share your thoughts over in the forums.

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