ISA Services Error.

Hi, I installed ISA 2000 standard edition on windows 2000 server. Installation went fine, after i install ISA and then go to monitoring-services tab i see all the services unavailable. When i check the services option in the administrative tools section all the services show running, however when i try to stop service of webproxy the process hangs and returns an error saying webproxy unavailable.
I do not have IIS installed on my system, neither DNS or WINS.
What could be causing this problem??
Please help me.

Regards.