So my computer crashed last night. Well, when I restarted, it would turn on but wouldn't go past the second black screen, so I had to reboot the OS. In the process everything from drive C was wiped clean. But Oblivion was installed on drive D. Now, here is my question. Should I reinstall Oblivion since the registry has been wiped clean, and then reinstall all the mods? Or will it not make any difference either way? My only issue with reinstalling is doing the same for the 400+ mods installed on D.

You don't need to reinstall all your mods. As long as the registry is pointing to your Oblivion game, it will automatically just look in the Data folder for anything that's there. So all you need to do is install the game itself.

You should redo everything that means installing the game and then adding the mods
My current game is running smoothly although I don't remember losing the registry, I can't install my DLC's now it doesn't see the game, when I put the DLC inside the game folder it just launches the game..
So the probably best choice would be to wipe it clean and install again, however for later usage when you make a stable game make a backup copy of the game since it will be much safer but it will probably use more room.
Take the non buggy stuff and one overhaul and thats it the rest of the stuff is small and simple and easy to replace or add so after install add the standard stuff ( COBL/OOO/SI/Frans...)

There's absolutely no need to reinstall your mods, they still exist fully intact in your Data folder. All you need to do is overwrite the game files. BTW, I doubt very much if you have 400+ mods installed as there's a 254 limit, after which strange things happen to your game.

@ Dark Hound

If your DLCs aren't seeing the game, then it's not installed correctly. There's something wrong with your registry. You should uninstall your game, clean up your registry with something like Auslogics Registry Cleaner, then install the game again. You don't necessarily have to lose your registry, sometimes they just get screwed up or corrupted.

Not if he's using Wrye Bash to merge them.

Just remember to copy/paste your data folder over your new install for Oblivion, as reinstalling vanilla Oblivion over your mods will overwrite parts of them and you'll have serious problems.

Good point. You should copy your old Data folder somewhere, then copy it back over the new one after you reinstall the game. All you really need is the the new registry to be updated, everything else can be exactly the same as the way you had it before. Provided of course it was working correctly then.

I am using wrye bash plus not all of them add to the limit, i.e. no esp.

Thanks for the pointers guys. My original install was on D, and I backed it up to C. Didn't really work out so well. lol
There are a ton of registry errors from having to reinstall C, so I'm using CCleaner to take care of that.

I just wanted to make sure that I wasn't harming 1. my computer and 2. the game, so thanks for the replies.