"Prevent access to 16-bit applications" in the Computer Configuration \ Administrative Templates \ Windows Components \ Application Compatibility section.
Vista / Windows 7:
“Click Start, click Run, type gpedit.msc in the Open box, and then click OK. This opens the Group Policy console.
1. Expand the Administrative Templates folder, and then click Windows Components.
2. Click the Application Compatibility folder.
3. In the details pane, double click the Prevent access to 16-bit applications policy setting. By default, this is set to Not Configured.
4. Change the policy setting to Enabled, and then click OK.
Impact of Workaround: Users will not be able to run 16-bit applications.”
Or (Windows 7):
In the Search field above the Start button, type (or paste):
edit group policy
then click on the link Edit group policy
User Configuration > Windows Components > All Settings > find:
Prevent access to 16-bit applications
then turn it on.
Affected Software
- Microsoft Windows 2000 Service Pack 4
- Windows XP Service Pack 2 and Windows XP Service Pack 3
- Windows Server 2003 Service Pack 2
- Windows Vista, Windows Vista Service Pack 1, and Windows Vista Service Pack 2
- Windows Server 2008 for 32-bit Systems and Windows Server 2008 for 32-bit Systems Service Pack 2*
- Windows 7 for 32-bit Systems
Non-Affected Software
- Windows XP Professional x64 Edition Service Pack 2
- Windows Server 2003 x64 Edition Service Pack 2
- Windows Server 2003 with SP2 for Itanium-based Systems
- Windows Vista x64 Edition, Windows Vista x64 Edition Service Pack 1, and Windows Vista x64 Edition Service Pack 2
- Windows Server 2008 for x64-based Systems and Windows Server 2008 for x64-based Systems Service Pack 2
- Windows Server 2008 for Itanium-based Systems and Windows Server 2008 for Itanium-based Systems Service Pack 2
- Windows 7 for x64-based Systems
- Windows Server 2008 R2 for x64-based Systems
- Windows Server 2008 R2 for Itanium-based Systems
Source
microsoft.com/technet
