I have ran Avast antivirus and it has found various "Win32:Spybot" viruses in the following files: iexplore.exe lmrss.exe messenger.exe msgn.exe msnins.exe netclnt.exe ntce.exe scvhost.exe scvhst.exe scvhest.exe winupdt.exe wuamngr.exe When I open program manager, it disappears! How do I get rid of these infected files without damaging my system files?

You have to turn system restore off, restart the computer and enter the safe mode(usually by tapping/holding down the F8 key during the boot sequence). Select Administrator and run AVAST's scan while in the safe mode. After the system is clean, restart and run AVAST one more time from the normal mode. You can turn system restore back on if AVAST has done its job of repairing/deleting the infected files.