ever heard of DDU?
pro tipp - run it in safe mode
I haven't. What is DDU?
What is the MAKE & MODEL of the AMD GPU card and Motherboard?
In my comment, I gave the link to DDU (DISPLAY DRIVER UNINSTALLER). Click on the orange link and it will take you to the website to download the software. It is free.
DDU is a software that is used to erase all traces of AMD, Nvidia, and Intel Display Drivers and software from your computer. It works best and it recommended to use in Safe Mode and the Internet must be disconnected from your computer. DDU can automatically boot your computer into Safe Mode if it is supported.
try this basic method to Uninstall and install AMD Driver packages:
install AMD driver:
1) Download the correct AMD Full Set of drivers from AMD Support. Make sure your Windows is fully updated via Windows Update. Windows Must be fully updated because the latest AMD Drivers requires all the latest "Optional" and "Recommended" updates to be installed.
2) Use Windows Uninstall to uninstall current AMD driver and software. Then use DDU (Display Driver Uninstaller) Display Driver Uninstaller (DDU) from Wagnardsoft (Display Driver Uninstaller (DDU) V220.127.116.11 Released. - Wagnardsoft Forum ) Forum in Safe Mode. This will eliminate all traces of the AMD driver and software from your computer.
Delete C: \ AMD folder from the Root Directory. Reboot and disconnect the internet from your computer.
3) Go to Device Manager and click "Display Adapter" and make sure you are on the MS Basic Display Adapter. If not, uninstall the AMD driver using Properties.
4) Try reinstalling the AMD FULL SET OF DRIVERS that you have downloaded manually. Make sure you disable the Internet to prevent Windows from installing a newer version. So configure windows to prevent it from updating drivers via windows update. So it has been mentioned to disable any anti-virus programs before installing AMD Drivers.
5) If the new AMD drivers installs and works correctly, delete again the C: \ AMD folder from the root directory. To save space on the HDD.
6) Enable both the Internet and Anti-Virus program (if applicable).
7) Go back to Device Manager and check your GPU card driver is working and identified correctly.
As I said in the original question. I've already uninstalled Radeon Software via Windows Uninstall as per software supports instructions and I can't reinstall because the website and link in software support has changed, so the only thing available to install is Ryzen Master, however I had the install file in my downloads and that seems to have worked.