Restructuring my LAN

I have a lan with about 25 PCs all with windows xp, 20 of which are under my control (i.e I can install stuff on them). It is currently all networked in a regular workgroup with a bunch of interconnected switches & a router. However due to the size of the network and the insufficient services & security in a workgroup I've decided to move to the Server/Client model. I'm planning to install windows server 2k3 but I would like answers & some advice.

First of all, I'd like to be able to monitor and preferably control the internet bandwith being distributed to the network to prevent a single user from ruining the bandwith for everyone. How would I be able to achieve that ? I'd like to achieve that in such a way that if the server is shut down I only lose monitoring & control over the network and wouldn't result in the rest of the network losing its internet connection. So any ideas ?

Another thing is all those PCs currently have a "public" account that has alot of stuff limited via group policies. Would it be wise to make a single user account in the new server/client model for use on all these PCs or an account for each PC is best ?

 

You will need to implement strict Policies and learn how to use Active Directory. Also, look into changing out the Home grade networking equipment and look for Switches & Routers that have Level 3 capabilities, and can be managed, such as HP's Procurve line. And the best thing that you can do for yourself, if you have not done so already, is take some classes in Networking at the local college, to help learn how to use Windows Server & structured networking.

 

Actually I know how to use the active directory and already have some courses in networking. So I should be able to follow any advice, I just have some difficulty trying to find a solution that would keep internet for the PCs w/o the server and still get some sort of monitoring & control over the network if the server is online. I also have no clue how to implement the bandwith throttling portion, I suppose I need some 3rd party tool ?

As for the hardware changing, I doubt it would be possible at this stage since I don't own it .