I have a similar problem, so I'll piggyback it onto this thread. Our computer is running XP SP3. At the beginning of September, I switched from Norton to McAfee. I used the Norton tools to completely remove Norton. I bought the installation CD for the three-PC copy of AntiVirus Plus 2010. Our CD didn't arrive until after our copy of Norton expired, so I downloaded the 30 day trial from McAfee. Around September 23rd, I attempted to install from the CD, but there were problems with activating for some reason. Around the 28th, I uninstalled the 30 day trial version and thought I had successfully installed from the CD.
However, I now think that something went wrong with that install that wasn't obvious. Two days ago I discovered based on symptoms that my computer was infected with some trojan that was causing my searches in Firefox to redirect. I found yesterday that our copy of IE8 was starting and then shutting down within seconds. I downloaded Malwarebytes Anti-Malware based on some recommendations, and it found a number of problems. McAfee real-time scanning also found those problems as Anti-Malware found then. To be safe, I tried to run a McAfee scan.
When I run McAfee scan, at first it doesn't respond at all. If I click the "Run a quick scan" or "Run a full scan" link several times, I eventually get a window for the scanner, with the "Completed" area showing "undefined%" completed, and it just sits there like that. I've left it there for over 20 minutes, and nothing happens. This is the same whether it's the quick or full scan. I suspect that the scanning system has not worked since I installed it.
I also tried setting up a scheduled scan for this morning, after the re-install, but it appears to have done nothing. What should I try next?
One other note. One recent software install caused problems with other software. ITunes 10 autoinstalled a week or so ago, and immediately killed our copy of Outlook. It had the symptom that things appeared then quickly disappeared (a lot like what happens with McAfee authenticate). I've followed the instructions elsewhere online to disable the dll that caused the problem for Outlook, but it's possible that ITunes is contributing to the problem. It doesn't seem like that would cause the scan engine to go nuts, though.
Messages consolidated & branched to own thread by: Ex_Brit for better attention on 07/10/10 11:46:50 EDT AM