I can provide a more specific troubleshooting guide based on those details!
Avoid "Driver Update" software. Always download directly from AMD to prevent malware.
If you have an AGP version of the card, you may need the AMD AGP Hotfix driver if the standard Catalyst package fails.
If you are having trouble with the installation, let me know: What are you using? Are you getting a specific error message ? Is your card an AGP or PCI Express model?