Drop down menu won't disappear from screen
Here are 2 different options depending on your operating system
1) Control Panel > All Control Panel items > Performance Information Tools
choose Adjust visual effects from the side menu. Uncheck "Fade out menu items after clicking".
2) Right click 'Computer' then go to 'Properties'>'Advanced System Settings'
Then choose 'Settings' in the 'Performance' box and uncheck "Fade out menu items after clicking"