If nothing is wrong with your setup, and simply want to move the modified setup, it is perfectly fine to copy the old Data folder on top of the new one after reinstalling.(Click the help icon in the lower-right corner of Bash's toolbar.) You will be moving the Oblivion/Oblivion Mods folder and a configuration files which can be exported, possibly along with a few other configurable files. (Bash and BAIN) See the backup instructions in Wrye Bash's ReadMe.(OBMM) OBMM users (reinstalling to a different location) can save OBMM's state by (Import/Export) exporting the active OMOD list and moving the OMOD directory (default: Oblivion/obmm/mods) outside of the Oblivion install folder (i.e., to the Desktop) temporarily, until OBMM is reinstalled.If you are moving Oblivion to another computer, whenever there is a step to move something 'to another location' move it to your flash drive or whatever device you are using to transport the files. Delete your Oblivion install folder (the one that contains the Data folder.).Delete your Documents/My Games/Oblivion folder.If you would like to keep your save files, move your Saves folder ( My Games/Oblivion/Saves) to another location.Note: This does not touch the folder in Documents because those files are generated as you launch and play the game, even the initial copy of most of those are not created during Oblivion's installation. Run Oblivion's setup from the Windows programs list (uninstalling the files belonging to the vanilla game).Reinstall Oblivion on top of the existing setup.

Uninstall all mods installed with utilities (i.e., deactivate all OMODs, uninstall all packages in BAIN).These instructions do not save any mods or utility configurations, only save files.

Below are uninstallation instructions for those uninstalling the game completely, moving a setup to a new location while maintaining mod and utility configurations and reinstalling Oblivion to the same location maintaining mod and utility configurations. Furthermore, with mods and utility configurations you may want to save, it can be hard to tell which files are necessary to save. Due to some bugs in Oblivion's setup and the fact that setup.exe does not uninstall all of the files that are generated as you play the game, uninstalling Oblivion can be a bit tedious.

How to install obmm with steam