Help! before I reinstall Windows

I get this error message when I try to uninstall Office 2007: 'Setup cannot
continue because a required file is either corrupted or not available. Run
setup again from the original source disc or download location.'

I'd like to keep Office 2007 but not ready to purchase quite yet. In the
meantime my trial has expired. What I
don't know is, is if I should leave the corrupt file(s) in my computer. I'd
like to reinstall Office 2003, but not sure if I should with the corrupt
file(s). As I'm typing I'm trying to get a good backup (even having trouble
with that) and considering a clean install of Windows. (hate when that
happens )

I'm just wondering if there is a better solution before I go to all that
trouble?