wonderwyrm: i still get the same error as before, even when i run it as admin
You might want to try from scratch, and have an eye on some Vista specifics:
1. Uninstall the game. Completely.
2. Log in as every user you tried to run or patch the game with and
2.1. navigate to Users<YOURUSERY>\AppData\Local\VirtualStore\Program Files
2.2. see whether there's a subdirectory named like the one you installed the game into
2.3. delete that directory
2.4. rinse and repeat with the other users
Now you should have a clean slate. The problem is that the masterminds in Redmont decided to virtualize filesystem access when the users does not have access to specific regions of the filesystem. So when you try - as regular user - to put something into program filesfallout, for example, it might end up in \Users\<YOURUSER>\AppData\Local\VirtualStore\Program Files\fallout instead. The bad thng about that is that this virtualization is based on some stupid heuristics and simple decisions. Executables and dynamic link libraries, for example, are never virtualized (so malware would not install into the virtualstore, either - very clever ;P).
In real life this means you're in trouble. Installation usually goes to program files, and the installer is usually launched from an administrator account (either by logging in as one or by being prompted by UAC). Once you start putting "things" (for example, the TeamX patch, which consists of data files only, but no executables) into that directory, they might end up virtualized -- and that means, NO OTHER user is going to see the modifications you just made, because file system virtualization - as you can see fro the path - is per user, not per system!
So if you want the least possible trouble, my advice is:
Install and maintain(!) software under a _designated_ admin account. For file system operations, use something like FreeCommander or whatever you prefer, and remember to always right-click and "Run as administrator" to avoid virtualization. You should be good then. Which lead us to:
3. Install and patch the game as described above ^_^
BTW: You can disable file system (and registry, works the same) virtualization via Windows registry or group management console (if your Vista version has the latter, home editions don't), but only use it if you know exactly what you are doing!