I have been running Avast and ThreatFire on a home computer that is used as a file server for about 6 months without any issues. I have been following this forum for a while and have been impressed with its helpfulness.
Recently, my daughter asked if I would troubleshoot two unresponsive computers that belong to a couple of her college friends. I was able to install and run Avast, Malwarebytes and SuperAntiSpyware on the first computer, a Sony laptop running Windows XP. With those programs, I successfully removed a "bunch" of malware and the laptop now seems to be in good working order.
The second computer, a Dell laptop, seems to boot into Windows Vista okay, but the desktop is not responsive, applications take a very long time to load and run, if they start at all. New applications cannot be installed.
So, I rebooted to safe mode, installed Avast and set it up to run a boot scan. The boot scan found Win32:Spyware-gen[trj] and two instances of "Win32:Adware-gen[ Adw]". They could not be repaired and since they apparently exist in the Windows directories, I was not sure if I could quarantine or delete them without affecting the system adversely. So, I completed the scan finding only those three issues, but without removing the malware. Once back to the Vista desktop, I still was not able to run an Avast on-demand scan.
An earlier attempt to use Malwarebytes from safe mode to remove the offending malware resulted in rebooting to a blank desktop where only the Task Manager could be brought up. Fortunately, safe mode still worked. I did a restore from safe mode and got the laptop back to its original unresponsive desktop.
Any suggestions as to the best way to proceed? Thanks!