Bit Defender anti virus software caused a storm over the weekend after a borked update bricked thousands of 64-bit Windows operating systems.
Apparently the problem was caused by a dodgy virus definition which falsely identified a number of essential system components as a well-known trojan, causing the OS to crash and fail to reboot.
Embarrassingly, it seems that the virus killer update also identified components of its own software as harmful, effectively making it commit suicide.
One user said, "Bit Defender's lack of response on this issue is very disappointing. They don't have any kind of information on the front page of their website, even thought this is a major outage with their product. They don't have anything in their Knowledge Base, either. The only thing I've seen so far from official BitDefender people has been a half-assed apology and no real solutions."
Bit Defender has advised users to use Windows Restore to get back to the last known safe configuration and has supplied a number of patches for XP, Vista and Windows 7 64-bit versions.