I am running avast 6.0.1367.
Every day at 1am, a full system scan is run.
Every day, at precisely 3:12 am, the system freezes, including the clock.
System is completely non-responsive. If I don’t run scan, everything is fine.
Boot-time Scan shows no problems.
Any ideas?
Does it freeze on the same file or its different each time?
In my opinion a daily full system scan is overkill. I find once a week is plenty. Especially with all of the real time shields that avast has. As far as the boot scan goes this is only necessary when avast recommends you do so. Have you ran a full scan with MalwareBytes and Super Anti-Spyware?
http://filehippo.com/download_malwarebytes_anti_malware/
http://filehippo.com/download_superantispyware/
Also, please provide more info regarding OS and any other security software you now have or ever had.
If any security software was uninstalled, how was it uninstalled?