AVAST is another free, but effective antivirus. I have used it for a
couple of years now and it does a bang up job, and is updated
sometimes twice a day. It has great detection, and in the last two+
years has given me no false hits.
As noted above, scans can take a long time. Hang with it though as if
this is a virus in your boot sector, once it finishes its scan, the
program will need you to reboot so it can scan your start up files.
Then it will finish up.
No antivirus/spyware is 100%, and some pick up things others won't.
Don't be afraid of the free stuff (remember though, they *love* an
donation or actual purchase!) as it turns out most of the free stuff
like AVAST, AVG, and Trend Micro test nearly as good or better than
Norton and McAfee.
They also take less resources from your machine, and if you delete
them, they are gone. Just try and get rid of Norton..... I have had
it on twice on two different machines, and it can't even uninstall
itself. There are bomb fragments all over the machine when you
uninstall, and if you don't run a registry cleaner it will still loads
remnants (or at least try to) of the program.
McAfee..... two commercial versions later, and too many false
positives to count. Both programs are bloated larger than the
Hindenburg, and while they test out well in most cases, you will find
the tests are run on newer machines with a lot of available
resources. If your machine is older, say more than a couple of years,
those two programs will slow your machine considerably.
Good luck, Zz. It sounds like this is an easy fix.