Loading windows installer whil opening office...

Question

i am working in a browsing center. here while opening any ms office applications like word ,excel it shows windows installer then application opening is get delayed. i am not able to open straightly double clicking the word file. it opens only the ms word not the file.. when opening file from menu by default it goes to my documents. if i try to change the source again the installer disturbs.... what can i do for solving it.. service engineer doesn't no any thing.. OS- xp, office ver- 2003 enterprise edition..