Reboot into safe mode by pressing F8 at boot, and selecting Safe Mode at OS selection.
Then, scan for malware.
If for some reason you can't get into safe mode (This has actualy happened to me before), you can always download a live cd such as knoppix, which is a good thing to have around, anyways. I believe knoppix comes with a windows virus scanner.
It may also be a possibility that you have too many startup services. In this case, you can edit which startup servicesby running msconfig and clicking on the startup tab. And of course remove any entrys in your startup folder.
Then, scan for malware.
If for some reason you can't get into safe mode (This has actualy happened to me before), you can always download a live cd such as knoppix, which is a good thing to have around, anyways. I believe knoppix comes with a windows virus scanner.
It may also be a possibility that you have too many startup services. In this case, you can edit which startup servicesby running msconfig and clicking on the startup tab. And of course remove any entrys in your startup folder.