Your computer really may have a "screw loose". These can cause electrical shorts inside the computer. Of course, you'll need to unplug the power cord before trying anything. First, pick up the computer case and rock side to side. Lightly shake it to loosen the screw and it should fall to the bottom of the case. Use tweezers to remove if needed.

There is now a built-in diagnostic tool within Windows that can be used to troubleshoot PC problems. Checking your memory should be the first step in diagnosing a computer problem. The Windows Memory Diagnostic Tool can be accessed at the Admin Tools section of the control panel.

When running the Windows Memory Diagnostic Tool, you can choose from three tests: Basic, Standard, and Extended. The tests can take a while and the computer will automatically be restarted at the end. The results will be shown at the next start-up. Bad memory should be removed or replace to keep from losing important data.