The computer appears to be getting a very processor intensive task just after starting up. I suspect Norton but try disabling some startup items. Click on Start - Run. Type in the word msconfig and OK. In the box that opens click on the Startup tab. Click to remove the ticks from any suspect programs and click OK to on each box exit. reboot the computer. If the problem has gone, then re-enable the startup items until it comes back. You will then have found the culprit.