PCS:Oblivion freezes at the main menu
Oblivion loads to the main menu and freezes there.
Causes and Solutions
Cause 1 - UAC Protection
Windows 7 and Windows Vista users have User Account Control (UAC) on by default, which prevents applications without administrator privileges from installing and modifying files. Of course, Oblivion has to modify a few files, such as its main configuration file, in order to work fully.
Solution #1: This issue affects many utilities for Oblivion, so the cleanest, safest method to avoid this and further related issues is to uninstall Oblivion (and all Steam games) and install Oblivion (and any Steam games) to a folder outside of UAC protection (i.e. C:\Games). The same applies to Steam, if Oblivion is installed through it.
Solution #2: It is possible to only disable UAC protection on the folder in which Oblivion is installed. Since Oblivion and other mods modify Documents/My Games, you may need to disable protection on that folder as well.
Solution #3: Another clean method (albeit a bit less safe) is to turn off User Account Control all together.
User Account Control