When you click on any Excel , Word or PPT file on any Browser, your Browser gets crashed. Even i have faced the same kind of problem, but finally i SOLVED the problem, just go to the
C:\Program Files\Microsoft Office\Office 12\OWSSUPP.DLL and delete OWSSUPP.DLL and then
Run the MS Office Diagnostic Tool in your start menu (MS Office/MS Office Tools) ,
It should find one error and fix it for you.
then restart your system .That's it your problem will be solved.