During recent times i came across this screen indicating that Microsoft Office 2010 setup is unable to proceed due to the following error(s):
Microsoft Office 2010 does not support upgrading from a prerelease version of Microsoft Office 2010. You must first uninstall any prerelease versions of Microsoft Office 2010 products and associated technologies.
Following can be a reason behnid this:-
1) You still have TP, Beta or RC of Office 2010. If you have any of them, remove it before you continue.
2) You might not have full installation of Office 2010 TP, Beta, RC but might have any component installed like Outlook Connector for Office 14 (2010) etc. So that needs to be removed as well. So left overs of any Pre-Release version should be present in your PC.
3) Something strange i came across, Visio is never been a part of Office, i was running Visio 2010 Beta alongwith Office 2007 when i tried installing Office 2010 RTM instead Office 2007 it came up with this same error message. And Yes! I had to remove Visio 2010 Beta in order to install Office 2010 RTM, isn’t it strange? as Visio and Project are not a part of MS Office but still their Beta, RC etc have to be removed inorder to install Office 2010.