Microsoft .docx format - fail!

I was installing a WinXP + Office 2003 machine for an acquaintance and of course let Windows Update get it to the latest patchlevel. During this process the MS GDI+ detection tool popped up and said the the computer had software which may be affected by the GDI+ vulnerabilities (correct, since I had Office 2k3 installed). Then it offered me a link to a .docx file to read for further instructions :-) Very, very smart.

BTW, does somebody know where is in Excel 2007 the "File Properties" menu??? I'm going back to my OpenOffice.org 3.0, however MS Office 2007 hijacked all my file extensions and I couldn't find an easy step to reset it to OO (maybe I just bite the bulled and uninstall/reinstall OO).