Setting Up Multiple User Accounts - Problem

I switched to Windows 7 recently and tried to set up multiple accounts when I ran into a problem.
I need to set up 200 user accounts on machine (dont ask me why lol) but once I reach close to 100 it locks me out. By lock me out I mean I cannot create any more new accounts, I cannot enter the UAC panel, I cannot manage any of the existing accounts including my own adminitrator account - in other words I cannot do anything under the 'user account' tab on the control panel. if I create one of the other accounts as an administrator it shows me the same results - actually it wont even go into the user accounts tab no matter how hard I click on it...
I tried this on both my machines - one running Family the other professional 64bit. Same result - one got to 96 accounts the otehr to 98 accounts.
Is there a limit to the number of user accounts you can run on Windows 7? I rememebr on Windows XP there was no limit (although the welcome screen slowed down to a crawl when i tried to set up more than 50 user accounts). Is there a way around this limitation if there is one? If there is a limitation is it with regards to these versions alone and perhaps the Business/Enterprise edition does not have this problem?
Any information would be appreciated.

Ive never run a server before...
This is a home laptop - would I even be able to run a server on it?

So IS there a limit that you know of with regards to the maximum number of user accounts one can run on a machine?
Also - where can I find more info with regards to running a server. Im sure ill need it seeing that Ive never run one before...