Turn off DEP in Vista
Data Execution Prevention (DEP) monitors programs and how they run from system memory,this results in many applications getting blocked by DEP in Vista.
It can be turned off or customized as per liking,the quickest way to turn on/off DEP is through the almighty command prompt.
Launch command prompt with administrator rights and type the following :
bcdedit.exe /set {current} nx AlwaysOn
This turns on DEP for all applications,not fun at all when you can't install any program after this command is executed :)
To turn off DEP,which is usually the case especially when games that run on XP without a glitch suddenly stop working on Vista (Manhunt comes to the mind) :
bcdedit.exe /set {current} nx AlwaysOff
In both the above commands,a restart will be necessary before the changed DEP settings can come into effect.
Enjoy.