Disable DEP in Vista:
1. Click Start
2. Click All Programs
3. Click Accessories
4. Right Click on Command Prompt
5. Left click on Run as Administrator
6. Click the Allow button if it asks you for permission
7. Type or copy and paste this into the command prompt window:
code:
bcdedit.exe /set {current} nx AlwaysOff
8. Hit enter and you should see the confirmation: Operation Completed Successfully
9. Reboot and DEP should be off.