I've been playing Morrowind for a while, but i've had a game saved for Oblivion also on my PC. I tried switching over to Oblivion and it's now saying I don't have the correct version installed. After looking around, I saw that this is due to the install being corrupt, although i'm not sure how this happened. I have a lot of time and mods put into my game as of now, as well as being pretty high up in levels. I'd like to backup my saved game if I can so I can reinstall Oblivion, but I have no idea how to do that or what files to backup exactly. Can anyone help me with this?

Your saves are located in your "My Documents\My Games\Oblivion\Saves" folder. Highlight the saves you wish to keep, right-click on any of them, select Save, navigate to a diferent location on your computer, right-click and select "Paste."

::EDIT:: You can also save your entire "Saves" folder too if you want.

Ok. I've actually read that is how it's done. But what about all the .esp's, Meshes, textures, etc etc? Am I supposed to save the entire Date File too?

If your goal is to preserve your old saves, no. You just have to save .ess files in your Saves folder.

::EDIT:: Unless you have mods installed and you want to reinstall everything the way it was. Is that what you're asking?

Yes, that's what I wanted to do. I have a lot of mods installed and the world set up nicely. I'd like to continue on from right where I left off.

You could make a copy of the files in your Oblivion and Oblivion\Data and merge them with a new install of the game. If you have OBMM and or Wrye Bash you have a list of your mods if you do need to go for the complete reinstall.

Ok. I imagine I could just copy my saved games and Data Files. I know I have OBGE and OBSE installed in the main folder, which I could just reinstall. Could I basically just delete all of that and just add my saves and Data Files folder to a new install and that would be fine?

You'd want to copy/paste your entire Data folder, in that case. If you also have utitlities like Bash or OBMM it might be worth copying the entire Oblivion folder. I've done this myself a few times and it works. After you do this it's a good idea to rename or delete the Oblivion.ini file in your "My Documents\My Games\Oblivion" folder and let the game generate a new one for you.

There is a chance that whatever problem you had before will just be duplicated. If your save has been corrupted, saving it is not going to make it magically start to work. And if it's something in your mod list that corrupted your save, it may just happen again once you get everything back in place. But it's worth a try. Good luck.

When you uninstall the game you don't lose any mods. All your plugins and stuff will stay in whatever folder you had Oblivion installed. Exception: if a mod overwrites any original files you will have to reinstall it.

However, looking at my "Oblivion Vanilla" folder, the game itself doesn't use that many files by default. In the Data folder there are just the standard .bsa files, the folder with the music, the folder with shaders, and one texture. So very few (if any) of your mods should have to be reinstalled.

If you have OBMM make a copy of the folders for it containing your OMOD's. You do not want to lose them.

I know I have a bunch of replacers in-game, but it's actually been a few weeks since i've played, so I have no idea what they are anymore. I'm backing up my entire Oblivion folder, then i'll uninstall Oblivion completely except fot the Date Files folder and hope for the best. If it doesn't work, at least i'll have a backup.

Here's something I do that you might want to consider. I keep a fresh copy of my vanilla Data folder on a separate drive (Oblivion+SI+DLC). If I want to revert to vanilla I simply rename the Data folder I'm currently using and copy/paste the virgin Data folder in its place. I generate a new .ini and I have an instant vanilla game back. I sometimes keep two or three differently-named Data folders (with different mod lists) in my Oblivion folder and switch between them on-the-fly.

So, in case you ever want to do this again, you might want to think about making a backup of your Data folder before you add your mods back in.

Yeah, I actually do that with Morrowind. I have a few different installs for 3 different characters, a fresh install and an install for working on mods. When I want to use a particular install, I just erase the end of the name and leave it as 'Morrowind' I don't mod for Oblivion yet, so I haven't done that to it. A fresh install of Oblivion would be a good idea to have handy though.