I came across a warning message from Avira while browsing the internet. It had detected something and proposed that I delete it. Virus or unwanted program 'EXP/Pidief.yag [exploit]' detected in file 'C:\Documents and Settings\Administrator\Local Settings\Application Data\Mozilla\Firefox\Profiles\hug6wxlm.default\Cache\705660DDd01. Action performed: Delete file As soon as I clicked OK, my system restarted. However, after getting the Windows loading screen, it restarted again.. and again and again. I cannot get past the Windows screen. It does the same thing when I try to run in Safe Mode, but if I press Esc, it successfully launches Safe Mode. I tried a System Restore for yesterdays date, but it didn't help. The bolded message above is an extract from my events log in Avira. Any idea what has gone wrong?