I have a custiomer who I tried to install SP2 on their XP machine. It will load to the point where it gives me an error. "HKEY\Dx Diag.DX DiagProvider to file C: windows\$NT Service Pack Uninstall $\reg 00177 Access is denied" It will not go beyond this point. What could be the cause of the failure or hangup from loading Service Pack 2. Thanks to all who answer.