I have a Windows XP machine that had Office XP Standard and I upgraded to Office 2010. When I preformed the Install of Office 2010 It said it removed Office XP but I have found it has not. When ever I start any of the Office 2010 applications Windows Installer begins with "Preparing to Install". This will sit not doing anything for 3 minutes before it just goes away. It does this at the start of any Office 2010 application and functions within the applications like creating a new email. If I click cancel on the installer it takes 3 minutes to cancel. I can see Office XP in Add / Remove Programs yet when I try to uninstall it errors out and does not do anything with message "This patch package could not be opened. Verify that the patch package exists and that you can access it, or contact the application vendor to verify that this is a valid Windows Installer patch package" I can use Office 2010 but with delay waiting for Installer to close. I am doing all this under an administrator account with full rights. I do not mind removing 2010 if need be to completely wipe Office off my machine as I can re-install it.