NEED HELP PLEASE

Hi to everyone who responds

I am running into a recurring problem and appreciate any help that may 
be provided to us

We run a p4 wintel box with a WINXP home O/S and a 7.1 netscape browser

We have zone alarrm / norton A/V 2004 and Webrrot spysweeper on this thing

Every month or so now - the clock starts changin time , the machine all 
of a sudden reboots on its own

and everytime we wanna sign into a banking page or hotmail - a 
javascript error pops up saying the browser (netscape)
isnt configured to accept cookies or enable cookies....

Problem is that IT IS - no matter what we do it does not work

  is this a virus / bad script - what the hell ? How do we fix this ?

any help is appreciated in advance