Instead of using "regedit" to open the registry editor, click on Start-Run, type "regedt32", then click on OK.. Now navigate to the path you mentioned, "HKEY_LOCAL_MACHINE\SOFTWARE\CA\CAPF", then RIGHT click on the "CAPF" key, choose "Permissions".. Give yourusername "Full Control", then try uninstalling again.

And YES, you DO need to make these changes from a logon with admin rights.

Hope this helps.