After removing Office 2007 from my computer earlier today after helping a friend with a few coding issues several weeks ago, my file associations ended up in a limbo where they weren’t associated with OpenOffice.org (.doc, .xls, .rtf, etc.). A few Google searches didn’t turn up any proper solutions, but Jan-Petter suggested that I should simply go to Add / Remove programs and choose to repair the installation. After finding the application in the Add / Remove Programs list and clicking ‘Change’, the installation dialogs from OpenOffice.org popped up. A few clicks later after selecting Repair and waiting for a few dialogs to finish, everything was back to normal.
And that’s how you reassign OpenOffice.org to handle all its file extensions again.
Unless you have deleted (or moved) the downloaded installation program file.