I’ve Got a problem.Can U help Please??

I have w 98SE.the problem is very strange.when I’m
playing Hearts In Yahoo.suddenly everything frozen
in my computer,the mouse,the buttons(Can”t use alt,ctrl&Delete for ending tusks)So i must restart
the pc. The Question is, Is This Somethimg related to Yahoo Server or something wrong On my PC. Hope I can find some 1 2 help.Thanks in advance.My E-mail ahmadidi2002@yahoo.com