Hey guys
I found that Utilman.exe refers to the Ease Of Access button on the logon screen. However the LShift + LAlt + PrtScn is actually controlled by a process called Sethc.exe also in the System32 directory. What I did was I made the following batch file:
rem This batch file will stop access to the High Contrast / Ease Of Access features. IE For Student machines.
rem press any key to continue
pause
cd c:\windows\system32
takeown /f sethc.exe
takeown /f utilman.exe
rem Now add disallow everyone permission...
pause
cacls %windir%\system32\sethc.exe /C /D Everyone
cacls %windir%\system32\utilman.exe /C /D Everyone
rem All done press any key to continue.
pause
Hope this helps someone!
Ian Alexander