is that deleted the files instead of uninstalling ..... or just can't uninstall?
if you just deleted the folders ... you've got a bit of a problem .... windows hates people who delete files without following "proceedures" (ie uninstalling)
if you have the CD ... just install then uninstall (you may have to repair then uninstall.
if no CD you can d/l a trial from
http://us1.trymicrosoftoffice.com/default.aspx
install then uninstall.
or finally ..... use the revovery disc .... an rebuild your system