Vista - programs associated with file extensions

I just installed Office Enterprise 2007. I can't associate either excel.exe with .xls file extensions or winword.exe with .doc extensions. I've tried using "Default Programs". I've tried right clicking on the file and using "opening with".
Also of note, none of the Office 2007 programs are displayed as programs that I can associate file extensions with. Office 2007 has been activiated. I even uninstalled and reinstalleed Office 2007 with no joy.

I can run excel or word and then open an existing file that way. But I should be able to double click a file and have it open it that way as well.

Anybody have any ideas?

right click on a file and choose open with.
Then select choose program.
If the Always open with box is not ticked then tick it.
Browse to the program you want to open it with and click on it.

Thanks. I have already tried that and it doesn't work either. As a trial I did the "open with" and used notepad. I can set .xls files to be opened with notepad or MSWorks spreadsheet ...I just can set it to open with excel.exe.

Files with other extensions work properly, ie double clicking on a .docx opens up in word, .xlsx opens up in excel.

I'm open to any other suggestions.