Note: Disabling UAC will lead to a less secure system, so be warned.
If you do this when running YANG and games on YANG, you are less likely to run into problems, as sometimes YANG can't write to config files as well as games such as xDuke and won't save your settings or sometimes the game won't start propelly because it reads a file that never got updated due to UAC protection. So if you run into problems you can try at least disabling UAC in Windows 7 or Vista.
Introduced in Windows Vista, User Account Control helps reduce malware infection by helping prevent potentially harmful programs from making changes to your computer. In fact, Windows Vista users have significantly fewer malware infections than people using Windows XP SP2. To help stop unwanted system changes, User Account Control asks your permission before proceeding with a change. In Windows Vista, you may see more of these prompts than you'd like.
You can simply drag the slider up or down, depending on how often you want to be alerted.
If you drag it all the way down to the bottom, you’ll have disabled it entirely.