file extensions in vista, how to fix them

I was having ton's a problems with truecrypt in vista because once I reinstalled truecrypt to a different location, vista lost its relationship to the extension .tc. Ahh, the pains of vista. Trying to correct it in control panel, didn't work. Finally I started digging through the registry and found where vista thought the applications existed. So I manually edited the program locations in the registry key:

HKEY_CURRENT_USER\Software\Classes\Applications

so for truecrypt it was located in:
HKEY_CURRENT_USER\Software\Classes\Applications\TrueCrypt.exe\shell\open\command