I have a Dell 5000e laptop 5+ years old that was upgraded to XP from Windows 98. It has worked great until about 2 weeks ago, when it started freezing up, usually while sitting at the Desktop screen. The only way to recover is turn it off and restart. I have run chkdsk /f and sfc scannow with no errors. It does it on battery power and A/C. No error messages occur. Any suggestions?