# Trouble using psychtoolbox on 64bit: SYNCHRONIZATION FAILURE!

**URL:** <https://psychtoolbox.discourse.group/t/trouble-using-psychtoolbox-on-64bit-synchronization-failure/2064>\
**Category:** Uncategorized\
**Created:** [May 27, 2013, 7:35pm UTC](https://psychtoolbox.discourse.group/t/trouble-using-psychtoolbox-on-64bit-synchronization-failure/2064 "2013-05-27T19:35:39Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![ajb12490](https://avatars.discourse-cdn.com/v4/letter/a/5f8ce5/32.png) [@ajb12490](https://psychtoolbox.discourse.group/u/ajb12490)\
**Post date:** [May 27, 2013, 7:35pm UTC](https://psychtoolbox.discourse.group/t/trouble-using-psychtoolbox-on-64bit-synchronization-failure/2064/1 "2013-05-27T19:35:39Z")

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Hi,   
  
I have been through the list of 10 error checking options following download (dpc latency checker showed no problems), and thus am now posting in the forum for help.   
  
I am running windows 7 on a 64bit with an intel hd graphics 3000. Whenever matlab starts now, I get the following message:  
  
 PsychStartup: Adding path of installed GStreamer runtime to library path. [C:\gstreamer-sdk\0.10\x86\_64\bin]. I have manually set path but continue to get this message..I figure it may be helpful to diagnose my main problem?  
  
I am able to see all of the psychtoolbox folders and all by calling 'help psychtoolbox'. When I use the demos or try to execute any of my previous experiments, I receive many errors:  
  
If I call a demo such as KbQueueDemo, it will start to run but when it comes time for the visual display portion, I get a PTB--ERROR: SYNCH FAILURE!---. I have tried everything and cannot resolve this issue. Additionally I get: "Error using Screen" output to the command line as well.   
  
I get the exact same error when I try to run other scripts I have written. An "ERROR - SYNCH FAILURE" and an "Error using Screen". Although this program runs well on my other windows comp.   
  
  
Thanks for any and all help.   
  
--AB