I got Oblivion a while ago, and enjoyed it massively, but it started to get boring so i tried a few mods. However, the mods i installed made it run very slowly and i tried to delete them. I had also installed the Mod Manager so when i deleted all the mod files i deleted this as well. In the program files i saw a file called 'obmm' andd i assumed this stood for Oblivion Mod Manager and deleted it. But now i go back on Oblivion and all the menu screens and loading screens work smoothly, but when i load a character only thing that loads is the HUD and sky. None of the landscape, items, NPCs or my own character load. Can someone please help me what i need to do???

Sounds like you may need to re-install it. What's your Spec's?

I have re-installed, and it made no difference. And I have no idea what a Spec even is... How would I find out?

Type DXDiag into the Start menu search bar, save the results, and post them here in [*spoiler] [*/spoiler] tags (remove the *s).

This tells us what hardware is inside your computer. What you are seeing is a common symptom of insufficient/dying Graphics hardware.

It did work pretty perfectly for months before, with only the occasional crash after VERY long periods of time playing, its only recently that its failed... My computer isn't the best gaming computer ever by any means but it managed to cope before... Its not my hardware thats the problem

Did you happen to use fix called Oldblivion in order to get the game to run? You really should post a dxdiag so we can see your hardware.
Did you make sure to delete the Oblivion.ini in My Documents>My Games>Oblivion?

Post a dxdiag.
XP: Go to Start->run, type “dxdiag” and hit enter. Click the Save All Information button near the bottom right. This will save a Dxdiag.txt in C:\ by default. Then open the dxdiag.txt and copy/paste the information into your post.

VISTA/Windows 7: Go to Start->Search, type “dxdiag” and hit enter, click the Save All Information button near the bottom right. This will save a Dxdiag.txt in C:\ by default. Then open the dxdiag.txt and copy/paste the information into your post.

You say you reinstalled -- but did you actually go in and delete all of the oblivion folders as part of that or just run the uninstaller ?? -- the uninstaller will only delete some of the files and will leave others in place which can cause problems at times (ie. it does not delete the Oblivion.ini file or any mod meshes and textures etc. that have been placed in the game folders) -- So try a complete uninstall which includes deleting both the My Documents\My games\Oblivion\ folder and the install folder (C:\Program Files\Bethesda Softworks\Oblivion by default)

Note I also said a symptom of DYING hardware. Don't ever rule that out. Computer components don't last forever.