My colleague gave me his PC infected with trojan last night.
It disabled Task Manager, Registry Editor, Safe Mode and System Restore.
Tried HitmanPro with Force Breach. scanned but couldn't clean. Abort.
Tried to install Malwarebytes, get error during arround 50% install. Abort.
Started CCE, updated, full scan, found 125 threats, all related to problem. Cleaned, computer works.
Very old machine, XP SP2, 240MB Ram, 40ish GB HDD... Scan done of over 4 million files in 3 hours.
One false positive [heuristics high] for old printer driver file, submitted as false positive.