how to prevent client pc's from becoming master browsers

I've been having a problem for a couple of weeks now in that client pc's are winning the master browser election and when they do for some reason I can no longer browse my domain from any of the domain controllers. And from the clients side I can only see certain clients and only one domain controller(server that's on the same net). But all mapped drives work fine and I can ping everything I just can't browse the domain which I need to for certain software I am using.
So I know that having a client as the master browser is my problem for some reason, cause when I restart those computers and force my pdc to take the role all is well again, until the next election and we start all over. So is there an easy way(group policy) to prevent clients from being a master browser. I read in another post on this site to make an ADM file, but I've really never done that before so if you could explain how to do that, or I could even push out a reg. entry if I knew what to edit.
Thanks guys, any help is greatly appreciated.