On Windows XP 64-bit in the ChipScope Pro Start menu entry, there is no "ChipScope Pro Uninstall last update" option to remove the latest service pack.
To work around this issue, use the command line. Run the following command from the ChipScope install "bin\nt" directory:
If a service pack is not installed, a message stating this is generated by ChipScope. This option will be added to the Windows XP 64-bit Start menu in ChipScope Pro 10.0.