I'll take a stab at this....
I assume that you have the the installation/drivers disk for the GF3.
On the desktop, right click. Properties, Settings tab, advanced (lower right), adapter, then click "change" off to the right.
Then choose "show all hardware," Next screen, scroll up the list on the left and select "standard display types"...in the right pane of the window select "Standard PCI graghics adapter (VGA)"
Click next and then finish. The system should ask if you want to reboot...yes, reboot.
When it reboots, click "My computer" icon on desktop, then the "C:" drive icon, then the "control panel" icon, then "Add/remove programs."
You should see a list of programs on the right....scroll down until you see "Nvidia 95/98 display drivers" (or something like that), highlight it by clicking on it, then click ok. You might also
check in that same list to make sure that there are no entries for your old Kryo drivers, if it is there, highlight it, and click OK as well.
That should remove the old drivers completely.
Restart windows, make sure that the disk is in the drive (Don't let the system auto start the cd installation, if it does, click cancel).
Right click on desktop, properties, settings, advanced, adapter, change, show all hardware, then click "have disk" at the lower right. Make sure the drive indicated is the letter of your cd drive (if not, change it), then click ok. Continue by clicking "next" or "Finish." Restart the system when prompted. That should do it.