illegal message

[Janet]

Can someone plz tell me why i keep getting the pop up you
have preformed an illegal operation then the browser
crashed when i click ok and clikcing ok is the only way to
get the box to go away i have windows 98se

 

[H Leboeuf]

This may be caused by a third-party program (adware, spyware, parasite).
Get AdAware and SpyBot and run them both. Keep them up to date.
Dealing with Unwanted Spyware, Parasites, Toolbars and Search Engines
http://mvps.org/winhelp2002/unwanted.htm