# PC: "Could not lock" error in Win **URL:** \ **Category:** Uncategorized\ **Created:** [January 14, 2005, 3:24pm UTC](https://psychtoolbox.discourse.group/t/pc-quot-could-not-lock-quot-error-in-win/979 "2005-01-14T15:24:28Z")\ **Posts on this page:** 1\ **Page:** 1
**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 14, 2005, 3:24pm UTC](https://psychtoolbox.discourse.group/t/pc-quot-could-not-lock-quot-error-in-win/979/1 "2005-01-14T15:24:28Z")
I'm a relative newcomer to psychtoolbox so apologies if there is an obvious answer, but when I try to run some of the demos (and my own code) on a Dell Optiplex GX280 (running 2K), I get 'could not lock' errors. Eg... MovieDemo aborts with ??? SCREENDFillOval: Could not lock device context for drawing. NoiseDemo aborts with ??? PutImage: Could not lock the offscreen surface for writing. Same code (and my own code) works fine on a Sony Vaio. Any thoughts? Thanks, George -- ------------------------------------------- Professor George Mather Psychology Department University of Sussex Falmer, Brighton BN1 9QG Tel: 01273 678342 Web: www.lifesci.sussex.ac.uk/Home/George\_Mather