My PC has a virus and I can’t install any anti-virus application to get rid of it. Does anyone have a recommendation for an anti-virus that will install on an infected system?
You might try ClamWin Portable on a USB thumb drive. You don't have toinstall anything. See: http://portableapps.com/apps/utilities/clamwin_portable
a linux live cd with have a lot an antivirus free, clam, bitdef, etc
There are several antivirus that offers month of trial periode so then you can decide which is best for you.
Avira free version
Try to scan the pc in safe mode with Clamwin
SARDU is a free* software that can build one multiboot support CD, DVD or a USB device
You could try running Dr.Web CureIt.
Other then that I suggest to get one of the various Anti Virus Live-CDs:
Avira AntiVir Rescue System
AVG RESCUE CD
However as always any removal of a virus should only be considered a temporary measurement. The safest option as always is to perform a re-installation sooner or later. For example parts of it can always reside in restore points or other none-accessible areas.