Can't run any third party programs on Win Server 2003 R2

Yesterday i ran into a really strange problem with my MS Server 2008 R2 (x64) and the problem is that i cannot run ANY third party applications. I can only run programs that are manufactured by Microsoft. Other than that it won't run and won't give any indications or errors.

So i figured it must be because of corrupt system files and i ran CHKDSK and SFC which did not produce any errors and both went well. But i still had the same problem. So at this point i tried looking for specific errors in Event Viewer.

There is some information like this (not error or warning) :

     The system file c:\windows\system32\commdlg.dll could not be copied into the DLL cache.  The specific error code is 0x00000000 [The operation completed successfully.
    ].  This file is necessary to maintain system stability.

and there are some like this :

The system file c:\windows\system32\userinit.exe could not be copied into the DLL cache.  The specific error code is 0x000003e3 [The I/O operation has been aborted because of either a thread exit or an application request.
].  This file is necessary to maintain system stability.

So i tried to run sfc /scanboot and still had the same problem. So i started to look for other problems such as group policies like and registry keys like RestrictRun which led me nowhere. So i am stuck in this state and have no idea what to do next other than a fresh install.

keep in mind that i have SEPM antivirus and malware is probably not the case. with that in mind what can i do ?