# No Subject

**URL:** <https://psychtoolbox.discourse.group/t/no-subject/1133>\
**Category:** Uncategorized\
**Created:** [January 12, 2013, 6:22am UTC](https://psychtoolbox.discourse.group/t/no-subject/1133 "2013-01-12T06:22:39Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Allen\_Ingling](https://avatars.discourse-cdn.com/v4/letter/a/a183cd/32.png) [@Allen\_Ingling](https://psychtoolbox.discourse.group/u/Allen_Ingling)\
**Post date:** [January 12, 2013, 6:22am UTC](https://psychtoolbox.discourse.group/t/no-subject/1133/1 "2013-01-12T06:22:39Z")

</div>

Dear psychtoolbox group,
  

I have searched and searched for an answer to my problem, but I could not find one. So I am bothering the group, hoping for a solution that is probably simple.

  

During installation of psychtoolbox 3.0.10, I get this message:

  

> > Running post-install routine...
> > 
> >   
> > 
> > Creating a startup.m file for Psychtoolbox at C:\Users\adam\Desktop\Documents\MATLAB\toolbox\Psychtoolbox\PsychInitialize\startup.m
> > 
> >   
> > 
> > PsychStartup: Adding path of installed GStreamer runtime to library path. [E:\gstreamer-sdk\0.10\x86\_64\bin]
> > 
> > Matlab release 2007a or later detected. Will prepend the following
> > 
> > folder to your Matlab path: C:\Users\adam\Desktop\Documents\MATLAB\toolbox\Psychtoolbox\PsychBasic\MatlabWindowsFilesR2007a\ ...
> >  
> > 
> >   
> > 
> > ans =
> > 
> >   
> > 
> > 3734.9
> > 
> >   
> > 
> >   
> > 
> >   
> > 
> >   
> > 
> > A very simple test call to the Screen() MEX file failed in AssertOpenGL, indicating
> >  
> > 
> > that either Screen is totally dysfunctional, or you are trying to run your script on
> > 
> > a system without Psychtoolbox-3 properly installed - or not installed at all.
> >  
> > 
> >   
> > 
> > This script or function is designated to run only an Psychtoolbox based on OpenGL. Read "help AssertOpenGL" for more info.
> >  
> > 
> >   
> > 
> > A first more diagnostic test would be to simply type Screen in your Matlab/Octave console and check what its output is.
> >  
> > 
> >   
> > 
> >   
> > 
> >   
> > 
> > The returned error message by Matlab/Octave was:
> > 
> > Last Error: Invalid MEX-file 'C:\Users\adam\Desktop\Documents\MATLAB\toolbox\Psychtoolbox\PsychBasic\MatlabWindowsFilesR2007a\Screen.mexw64': The specified module could not be found. (MATLAB:invalidMEXFile)
> >  
> > 
> > C:\Users\adam\Desktop\Documents\MATLAB\toolbox\Psychtoolbox\PsychOneliners\AssertOpenGL.m,95
> > 
> > C:\Users\adam\Desktop\Documents\MATLAB\toolbox\Psychtoolbox\PsychtoolboxPostInstallRoutine.m,665
> >  
> > 
> > C:\Users\adam\Desktop\Documents\MATLAB\toolbox\DownloadPsychtoolbox.m,820
> > 
> >   
> > 
> >   
> > 
> >   
> > 
> > Screen() or online registration failed to work for some reason:
> >  
> > 
> >   
> > 
> > Check the troubleshooting instructions on our Wiki (Download section 
> > 
> > and FAQ section, maybe also the Bugs section).
> 
>   
> 
> One thing i noticed, is that my gstreamer path is not actually in an E drive (there is no such drive on this pc). Is that causing the problem? How could I change this default setting to C:\gstreamer-sdk\0.10\x86\_64\bin ?
>  
>   
> 
> I am using windows 7 64 bit. I have installed GStreamer for windows 64 bit (runtime) and Microsoft Runtime Libraries for MSVC 2010
>  
>   
> 
> I really need psychtoolbox for syncing stimuli presentation with the screen refresh/vertical retrace. If anyone knows how to do this without the psychtoolbox, that would also solve my problem ...
>  
>   
> 
> thanks