Basically I want to reinstall Oblivion, but to a separate place. Basically this would be for testing and such without all of my add-ons. It gets tedious going though and un-selecting and re-selecting all of the add-ons all the time. I don't really wanna just copy and paste Oblivion over for a few reasons. First, there are some add-ons I have that change base files. Second, there is a lot of junk from deleted add-ons that are still in there. Last, I have everything unbundled and such so it is about 18 GB worth of files, and even with my good processor, that would take a while.

Oblivion doesn't really take well to multiple installations, as it stores critical data (ini file, and your saves) in the My Games folder..... both installs of the game would want to use the same info..... (and then, there is the plugins.txt file, that hides yet someplace else.....) There are a couple different utilities that 'simulate' multiple installs... but, I have zero experience with them, so, can't really make any recommendations there.

The easiest method I have found to do this is to rename both of your current Oblivion folders (ie. change both Oblivion folders to ModdedOblivion -- then run the Uninstaller (this will not actually delete anything since you have renamed the folders and the uninstaller will fail to find them but it does clear the registry entry so that you can reinstall a fresh copy !) --- Once it finishes reinstall Oblivion from the Disk (downloaded file if using Steam version) to the same folder you were using before - Now Rename that set of Oblivion Folders to UnmoddedOblivion --- Now all you have to do is rename the 2 folders appropriately each time you go to run the game off of a different set of files (ie. if wanting to play rename the 2 ModdedOblivion folders to Oblivion and play --- when switching rename the 2 Oblivion FOlders to ModdedOblivion and then rename the 2 UnmoddedOblivion Folders to Oblivion to run testing ---- JUST BE SURE that you keep the sets of folders both renamed together or it may result in problems ! (What I do is rename the Oblivion folder after each session so that they sit in the UnmoddedOblivion and Modded Oblivion folders so I do not have to remember which I used last and then before playing or testing I rename the corect set to Oblivion when starting - thus avoiding getting them mixed up !