After deleting my most recent restore points, switching ownership, and changing security settings I can no longer open up Microsoft Office 2007. An error message pops up saying, "The action is only valid for products that are currently installed." when I click anything from Microsoft Office. The programs in my Add/Remove Programs window also do not show at all, with exception to the ones I added the day I performed these changes.
So then I wondered, maybe I can reverse these changes, but I still have no restore points. I thought maybe I have to reinstall MS Office... probably, but I don't know where the disk is. I went to Ninite.com to install the trial and it tells me in an error message, "Skipped (already installed/update not supported)." So is it already installed or not? Please help.
The issue is from you playing around with security and ownership settings. Did you keep track of exactly what you did? There are several way to restore default security settings but they are not easy for an average user http://support.microsoft.com/kb/313222
Aside from that, you will need to backup your files and do a clean setup of Windows and re-install your programs again.