During the upgrade, your Windows NT 4.0 third party video driver was replaced by a standard Windows 2000 video driver for your adapter.
To resolve the issue:
1. Download a Windows 2000 driver from the adapter manufacturer and place it on a diskette.
2. Control Panel / Display.
3. Properties / Settings / Advanced.
4. On the Adapter tab, Properties / Driver / Update Driver.
5. Press Next / Display a list of the known drivers / Next.
6. Press Have Disk and insert the diskette from step 1 in the A drive.
7. Press OK.
8. Press Finish.
9. Close all open windows and restart your computer.
When you log on:
1. Control Panel / Display.
2. Properties / Settings / Advanced.
3. On the Monitor tab, Properties / Driver / Update Driver and follow the on screen instructions.