AC12 installation error for new user pls help.

[Anonymous]

Hi I'm new to archicad, I get a copy of evaluation CD in a exibition lately in the cd it had trial AC12 and Trial Artlantis Stidio V2. I install both, for artlantis studio V2 = no problem. But for AC12 I had this error shown "This application has failed to start because GSRoot.dll was not found. Re-installing may fix this problem." I had re-installed but still showing same error?!?!? also I notice that in the working directory is has no archicad.exe or any application start up file in the working directory "Program Files\Graphisoft\ArchiCAD 12\" after installation? I will love to have this fix and trail with artlatis studio V2 pls help.... thanks in advance..