I have been having a problem with my computer with avast 4. Though installed it was not shown in the task bar. It would not allow re installation either. Finally I had to format the disk and install OS afresh and then install avast 5. It went thro installation and also completed a system check. A day later, I dont find the icons in the task bar. When I invoke the exe file, avast doesn’t start. The other thing I notice in the system is that the ctrl-alt-del has been disabled.
May I request some senior member to guide me as to what could have gone wrong.
Most probably your computer is infected, deeply than format could have cleaned it.
If you have formated the disk, I suggest you use Partition Wizard to delete all partitions and also rebuild the MBR.
Then reinstall Windows and avast as soon as you can log into Windows.
Update Windows and avast.
Other way would be general cleaning procedure:
Clean your temporary files.
Schedule a boot time scanning with avast with archive scanning turned on. If avast does not detect it, you can try DrWeb CureIT! instead.
Use MBAM (or SUPERantispyware or even Spyware Terminator) to scan for spywares and trojans. If any infection is detected, it is better and safer to send the infected file(s) to quarantine (Chest), rather than simply deleting them.