Avast Boot Scan won't schedule

[headache62]

I cannot into my computer except in Safe Mode (logging in regularly just causes an immediate log off) and when I try to schedule a boot scan in Avast (run as administrator in Safe Mode) the settings immediately reset and the scan won't schedule or perform on startup.

I'm using a Sony Vaio laptop, Win7 home premium 64bit.

[Pondus]

have you just installed avast ?
what AV did you have before avast....was your Vaio delivered with a preinstalled AV ?
did you remove it before installing avast ?
have you run a removal tool to clear any leftover files that may conflict ?

[headache62]

have you just installed avast ?
what AV did you have before avast....was your Vaio delivered with a preinstalled AV ?
did you remove it before installing avast ?
have you run a removal tool to clear any leftover files that may conflict ?

I had Avast installed for probably 18 months until the problem started last Sunday.  Then I couldn't log on - it automatically logged off every time unless I was in Safe Mode.

I had Norton before that, but I uninstalled it before installing Avast.

I never had a problem until last Saturday - then I had an icon on my taskbar (Evernote, specifically) seem to "float" midscreen above everything and I couldn't do anything about it.  I restarted and wasn't able to log back in - the computer went straight to "Logging Off" on login.  I can log in on Safe Mode, but I can't update Avast or schedule a boot scan - the settings simply revert to "not scheduled" when I try to set it.  I've tried running it as Administrator while in Save Mode.

Thanks for the help - I'd really like to get this resolved.

[headache62]

*bump* - anyone have any ideas?

[Pondus]

follow the guide here and attach the OTL logs so Essexboy can have a look inside

http://forum.avast.com/index.php?topic=53253.0