Windows 7 and Office 2007 enterprise

Hello,
I have a problem with office 2007 and windows 7.
The problem is that after i have installed the office 2007 enterprise, i have seen that word is not the default program for the extension .doc
So i have done the operation for set it as default program, i have searched the extension .doc, i have selected winword.exe (word wasn't in the window of suggested program) then I was surprised because after that was selected nothing has done. I have tried many times this operation but always failed.
Anyone can help me or suggest how to modify it trough regedit?
Tks and best regards
Chorro