Vista - Need some help with security.dll

I'm getting this kind of error when trying to play Lord of the rings online
TurbineLauncher.exe - Bad Image
---------------------------
C:\Windows\system32\security.dll is either not designed to run on Windows or
it contains an error. Try installing the program again using the original
installation media
or contact your system administrator or the software vendor for support.
---------------------------
OK

I'm not getting any help from the lord of the rings online support, so I
thought about that I'll post it here. So what I need is some info on
security.dll, whats it for, what programs use it etc... so I could isolate
what is causing the error. I know that security.dll is somewhat used with
..NET Framework 1.1 what lord of the rings online uses, but could anyone shed
any light to this or a solution? I'm thinking my security.dll is somehow
become corrupted but I cant replace it from another vista installation,
because it just gives access denied. I think full vista reinstall would be
only help to this, but I'm not going to do it just for one game, because
everything else is working nicely. I'm running Vista Ultimate 64. So, Any
ideas?