laptop freezes after ending internet session

Emachines M5312
2400+ Mobile AMD Athlon EX-M
512MB, 60GB
microsoft home edition XP
5.1.2600 SP2-updated
Norton AV 2004-updated
Adaware SE personal-updated
netzero platinum dialup (no hispeed)

I can get on the internet just fine. But, getting off leaves my laptop frozen. The screensaver and system tray are still there as well as the ISP's icon. The icon is suppose to go away leaving the computer freed up. Yet, I have to power-button off and on to unfreeze it. It happens all the time.
First thought this was normal until reasoning set in. (new to pcing) "Why turn off a computer just to start it up again in order to use it"?
Talked to (e-mailed) ISP support quite awhile ago about it, and they said something about the graphics setting may be too high and to turn it down.
I was afraid to try anything, being new and all.
But, just for the record, I regularly use Adaware, Norton, delete temps and have defragmented. Use disk cleanup, too. I have all updates including XP's. Even tried the OS standby,restart, and turn off options instead of using netzero's toolbar "disconnect' button to get off the net properly. Same thing happens-the freeze. Keyboard is nonreponsive too until the restart. I close all windows as well beforehand as well.
Can you help? Thanks

 

Hi
Solved the problem.
Thanks to ALL