The 80gb hard drive became full and I bought an external hard drive and connected it yesterday. Today I started up the PC and windows won't start up. The PC just says windows is starting up. Can someone help me?:confused:

Disconnect the external hard drive and start it back up again. Is it a USB connected drive? Connect it after the system starts up and see what is on that drive.

Or, was your disk so full that Windows can not start up now? Try starting the computer up in Safe Mode and do some disk cleanup.