I agree with Jarsong that your troubles are pointing more in the direction of a hardware problem. I can also tell you that turning off your startup services won't always diagnose a software problem with a particular program. If you uninstall your Norton anti-virus program and reboot, you'll know in a minute or two if that was the problem. If it is not the problem it is simple to reinstall. Then you can concentrate on your hardware compatibility. Just don't underestimate the troubles that anti-virus software can create with other programs. Did you disable the Norton when you installed your 3D cad software and then enable it after you rebooted?
Good Luck, Wayne...
Good Luck, Wayne...