Windows installation

An update for the AVG 8 antivirus software for Windows 2000, XP and Vista released Saturday mistakenly warned that the Windows system file user32.dll was a Trojan horse. The problem affected the Dutch, French, Italian, Portuguese and Spanish versions.

AVG Technologies immediately corrected the problem for both free and paid versions of its software. If users acted on the update's warning, the user32.dll file was deleted, leaving Windows XP systems endlessly rebooting or unable to reboot.