I am using Bitdefender Anti-Virus Plus on a Windows 7 machine.  It appears that Bitdefender let through a virus called adware.agent.nxr.  After my problems started, I ran a Bitdefender scan and the report stated that this virus was present (in my Windows\temp directory), but that Bitdefender could not remove it.  I have since tried using other software to try to get rid of it, but nothing finds it.  I have cleaned out the Windows\temp directory, but the problem still exists.  Now when I rerun the Bitdefender virus scan, the report says no threats were found. (Maybe bitdefender doesn't report the virus again after found the first time???).
The symptoms are that if I try to open more than 1 or 2 windows/tabs in Firefox,  MANY additional windows and pop-ups automatically open, trying to get me to download other software.
Can anyone make any suggestions as to how I might get rid of it?  Or am I just going to have to do a clean install of my OS (and of course, I really don't want to have to do that...).  Thanks in advance for any suggestions.
Mark