In Win7 when viewing WPF applications (Expression Blend for example) I sometimes get strange rendering artifacts. It seems to be Win7 specific, or at least the drivers I have for Win7, since the same application can run on different environments and end up looking perfectly fine.

If you find yourself seeing strange things that don’t appear to be correct you can try adjusting these registry keys to see if it helps. I’m assuming these issues will be fixed by the Windows team / Video card manufacturers once Windows 7 is officially released but in the meantime this might help you resolve some of your own UI bugs.

Disclaimer: Do not edit your registry without backing up a copy first. Editing the registry can destroy your operating system if you don’t do it correctly, so use the below information at your own risk.

On Win7 x64:

Key Path: HKLM\SOFTWARE\Wow6432Node\Microsoft\Direct3D\
Key Name: DisableThreadedDDI
Key Type: DWORD
Key Value: 1

On Win7 x86:

Key Path: HKLM\SOFTWARE\Microsoft\Direct3D\
Key Name: DisableThreadedDDI
Key Type: DWORD
Key Value: 1

If you change these keys don’t forget to change them back after Windows 7 is officially released!