If all fail, check the file skyrim.INI under the installed directory (in Vista64, it's c:\Program Files (x86)\Bethesda\The Elder Scrolls V -Skyrim\Data). Search for uGridsToLoad and changed it to whatever the previous value of uGrids which was higher than the default 5. It should load the saved file and then you can follow the procedure above to switch it back to 5.
ATI & NIVDIA procedure are all the same because it changes the game profile and has nothing to do with the driver (theoretically). Just do the uGrids re-initialize section and ignore the rest. (Copy that section from the above linked procedure)
1. Backup SkyrimPrefs.ini, Skyrim.ini and your Skyrim ‘Saves’ folder.
2. Right click on Skyrim.ini in My Documents\My Games\Skyrim and uncheck ‘Read Only’ in the file’s properties.
3. Load your last save game.
4. Press tilde on your keyboard, most commonly placed directly to the left of ‘1.’ If it is elsewhere, the keyboard symbol should be ` or ~.
5. In the now-visible in-game console type setini “ugridstoload:general” 5
6. Hit Return on your keyboard.
7. Type saveini
8. Hit Return on your keyboard.
9. Type refreshini
10. Hit Return on your keyboard.
11. Close the console using tilde.
12. Create a new save game.
13. Exit Skyrim.
14. Delete Skyrim.ini in My Documents\My Games\Skyrim.
15. Reload the Skyrim configuration tool.
16. Close the tool.
17. Re-tweak Skyrim.ini if necessary (and SkyrimPrefs.ini if it has since been modified).
18. Reload Skyrim and your most recent save.
19. Enjoy the game.
Edited by AnonChicken, 11 December 2011 - 12:25 AM.