I've been playing this for a few hours after getting it for free thru Amazon. I keep getting these seemingly random screen freezes where the video stops but all the sound keeps going. I can even open close inventory, jump, sheath weapon, cast spells, etc but nothing happens on the screen, I just hear it happening. If I spam alt-tab I can eventually get back to desktop and then if I select Oblivion from the task bar it comes back like nothing ever happened. Does anyone know what is happening here???

I have no mods and play on AMD 3600x with a 5700xt.

Are you using Galaxy? If yes, install standard non-Galaxy Oblivion ("direct download") and try to reproduce the problem there. If you are successful, please report back here, with more technical details please (I'd also try different graphical settings, and Alt-Tabbing is unikely to help you with this - use the in-game menu or the task manager to exit Oblivion).
Otherwise it's a Galaxy problem. I can't help you with that, as I don't use Galaxy.

PS: To be on the safe side, it may be better to uninstall Galaxy-Oblivion before installing non-Galaxy Oblivion. If you do it, you better make sure that your savegames are backed up (either you copy them manually to some other folder, or you use Galaxy functionality, if that's possible).