Overheating!

[sean]

That beeping is your motherboard overheating, its leting
you know its getting too hot. The reason it stops when you
goback to the desktop is becouse the comptuer isnt being
used as much and its cools down right away. Make sure you
have enugh ventalation in your pc. get an extra fan if you
have to

 

[Nathan McNulty]

This was also one of my thoughts. I think you pressed the wrong button
or something, but you need to reply to the original message so they can
see your help.