DeXtmL

hello,

AFAIK, vista SP2 should NOT be the cause of the problem. Starting from catalyst 9.1, SP2 is supported by AMD. i also searched the web, hardly to find any issue about this.
i think WHQL certificated drivers are proven for great compatibility.

Your problem may be caused by some other unrelated issues. You can proceed safely to install SP2.
In case you are unsure about the impact, contact your vendor for compatibility info.

Before upgrading to SP2, make sure you have minimum apps installed, best if your OS is clean -- this can avoid inter-software damages.
[However, perhaps you have already installed some vital programs. i advise you NOT to uninstall them if you did follow a correct way installing them.]


about the Windows.old:
it's the folder that backs up your previous windows copy, which is not functional anymore.
You can, of course, copy your important data to a new location.
But for programs, you have to reinstall them all. (That's why i mentioned if your system has massive apps registered, reinstallation could turn out to be a nightmare.)


Hope this helps

Dex