I have to configure some PC in XP and give as less previlage as I can. How can I do that in XP? Is guest account good enough? I want to block sites like facebook, hi5 etc etc. Messengers should be disable as well. Basically it is an school network environment and its very vital that it block these services.
This networking will be done for about 15 to 20 PC. Its for students and I don't want any such sites or messenger service to open in school PC.
Using a group policy that is controlled by your schools server could stop access to these applications and websites if set up correctly, unfortunately I don't know how. It would work though, my friend has done it many of times.
Actually the network is already setup and I don't see any server computer there. So, my best chance of limiting these sites and services is by giving less previlages to computers. Does any software exists that I can install as an administrator and block those sites and services for other users?
Yes, as stated above you use group policies and make all students of one group with restricted access. You then install a proxy server that caters to schools and blocking things students shouldn't get to and make all computers route through the proxy and if they don't they don't have web access.
If you can't do these simple tasks you shouldn't be the administrator of a school, sorry.