I’ll show you how.
1. Go to the Start menu and select Run. Now type Regedit and hit Enter.
2. The Registry Editor will appear on your screen.
3. Now, open the folder HKEY_CURRENT_USER\Control Panel\Desktop.
4. If you don’t see then do the following: right click on a blank space in the right pane and select New\String.
Change the name in the new value to MenuShowDelay.
You should see a MenuShowDelay value.
5. Now that we have the MenuShowDelay value, double click on it and enter 0 in the value data field.

This sets the start menu delay to 0 milliseconds.

Speed up your Start Menu screenshots..