The symptom(s) you describe are most often due to malicious invasion. See
the Security (second) link in my signature. Make sure to visit Jim
Eshelman's Parasite pages, especially http://aumha.org/a/quickfix.htm After
doing all of the things we suggest, see
http://harrisonrj.home.comcast.net/step_by_step_pc_cleaning_process.htm
especially Step 4.

Yes, there are some redundancies in the above, but you have to remember one
important thing about antivirus, antispyware, etc. *None* of them are 100%
thorough. It takes scanning with a variety of scanners to be reasonably sure
of a clean system, and even then, there's no 100% guarantee.

If you clean up and find that the problem remains, then come back and we can
trouble-shoot. But IE and OE are the applications most affected by viruses
and spyware, and it makes no sense to try to t-shoot until you're reasonably
sure some malware isn't involved.