2 xp and 2k server

[racerxfactor]

i have three computers networked. 1 2k pro working as a server/router to two xp machines. usually when i do file sharing between one xp machine and the server it works fine. but as soon as the third machine turns on i lose all file transfer privilages. i have no set ip addresses to either xp machines just b/c xp is so darn good with finding interent connections. in either case when i did set ip addresses it did the same.

once one of the computers was a 2k pro machine also with an ip and the same thing happened. hope that info helps more.

any suggestions? what's going on?

anything would help, and thanks in advance.