I wouldn't trust a secondary source for GPU drivers unless they're like hugely reputable - lots of those driver sites are just fronts to get you to download and run their installer which deploys loads of malware/adware/etc.
Stick to the source - try AMD's official stuff and if that doesn't work, it's time to get a new card. It looks like AMD support for the X series cards ended after Vista, but that doesn't necessarily mean the Vista drivers won't work in Windows 10. You could even try running the installer in Vista compatibility mode if they don't work normally. Pro tip: unselect all the unnecessary stuff like Catalyst Control Center blah blah blah when you install Catalyst Software Suite. Select *only* the driver, the rest of it's totally unnecessary, especially for an X series card:
http://support.amd.com/en-us/downloa...Vista%20-%2064