office xp not working

After installing xp upgrade (previous os me) office 2000 stopped working. When trying to install xp office pro the installation process stopped and I got an error message – Microsoft Office setup cannot continue because the installation source has been corrupted.- the cd is fine as it installed ok on another pc. The pc was infected with the welcha worm and msblast virus which has been removed. Also when trying to open incoming mail in outlook express the program shuts down.