Wrye Bash encountered an error. Oblivion.esm: File is required, but could not be found

[Sheaba]

I'm trying to learn how to mod Oblivion but Wrye Bash keeps giving an error. I can't find Oblivion.esm file anywhere on my computer. I tried uninstalling and reinstalling Oblivion but that didn't work. What do I do?

[lmstearn]

Hi, and welcome to AFK Mods.

Sounds like Oblivion is installed in Program Files (x86), can it be installed somewhere outside that folder?