We need a closer look at what's happening.
Please download Hijack this
Copy it into its own folder, doubleclick HijackThis.exe, and hit "Scan".
When the scan is finished, the "Scan" button will change into a "Save Log" button.
Press that, save the log, do Ctrl-A to Select All, and copy its contents here. Most of what it lists will be harmless or even essential, don't fix anything yet.