You want Office 2007 to accept Office 2003 Proofing tools?
If you update from Office 2003, the Office 2007 installer will automatically accept any proofing tools (spellchecker, grammar checker) you had installed before. You cannot, however, install the Office 2003 Proofing Tools directly onto Office 2007.
If you happen to already have installed Office 2007, here's a
trick to make it work.