IIS problem on Win 2k server

Hi..

My question today to all the experts out there is this :
I installed MS Software Update Services(SUS) software on the server which was hosting/running our intranet and other important web projects on default port 80. As soon as this was installed our existing web projects were not browsing. Immediatily I uninstalled the SUS software. Even then the sites were not to borwse.

I uninstalled and reinstalled the IIS several times but no luck.
Even IIS admin pages on entering http://localhost
is also not getting. (http 500- Internal server error.)

This server is also our BDC for our network.

Any suggestions to over come will be appreciated greatly.

Thanks & regards,
Parameshwar