Another minor and easy tweak to remove any delay from menus sliding out. For this you will need to use regedit.
1. Open regedit by going to Start -> Run..., then typing 'regedit' and pressing enter).
2.The key you need to change is located in HKEY_CURRENT_USER | Control Panel | Desktop.
3. The actual key is called MenuShowDelay . All you have to do is change the value to 0.
4. Remember, you will have to re-boot your computer for this tweak to take effect.
