There is 4 ways (reasons for why Oblivion (or any Elder Scroll Game) would fail.)
1. Your System failed to meet requirements for Game
2. your save files refer to mod files that are no longer installed in your game and are critical to continue run your game (ie custom race or system patch).
3.) due to a great many mods your system memory can't handle running both the game and the OS at the same time.
4. you have a corrupted copy of the game (only solution to this unfortantly is to replace the disc (if you downloaded it illegally you need to start getting your games from a reputable source)
Solution
to the first upgrade and or replace the computer
to the second either reinstall the custom race mod or in case of latter just revert to a save before the missing mods
and the third well if you have open memory slots add more memory, if not all i can suggest is to tweak your mod order .
Only after installing a mod that someone made.
To kill any kind of ghost or spirit in TES 4: Oblivion, you need to either use spells, or enchanted, silver or daedric weapons.
You cannot buy it, it never becomes available for sale regardless of your level.
TES IV: Oblivion features the province of Cyrodiil only. It does not allow you to travel to other provinces, such as Morrowind - unless specifically added by a mod you have installed, of course.
Did this ages ago, but from memory I think you have to follow her to where she is talking to the gatekeeper and is crying as she talks to it, then you have to run in when she leaves, and she's dropped it on the ground.
Yes, there is a demo of elder Scrolls Iv oblivion. Go to www.youtube.com and but in "Oblivion trailer" or "oblivion demo" and you'll find what you're looking for.
the tes4 construction set is not included in The Elder Scrolls 4: Oblivion game of the year edition but you can download it from: http://www.elderscrolls.com/downloads/updates_utilities.htm
bruma
The Elder Scrolls IV: Oblivion does not have trophies
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The Ice Blade of the Monarch is in TES 3 Morrowind, not Oblivion. You may be able to find a mod that will add it to the game but I'm not sure.
It lets you carry more than your usual weight capacity.