FIX MSDTC
If MSDTC is corrupt..
and if you can't access anything in mmc and get com+ errors in the event logs or when browsing dynamic pages. then try this to fix things up:
cd %systemroot%\system32
msdtc -uninstall
msdtc -install
Then to glue things up in IIS:
cd %systemroot%\system32\inetsrv
rundll32 wamreg.dll, CreateIISPackage
check this discussion topic : http://forums.asp.net/1174321/ShowPost.aspx