[Neptune Towers]

When ever i'm playing a game it will take me straight back to my desktop every 5 min (it's like as if i pushed alt+tab which i did'nt), it gets really annoying when i'm in a middle of a game aswell, i can return to the game in no problems but it happens every 5 mins, and there nothing wrong with the software because i have tried it with other games plus my pc never actually used to do this until recently, any tips would be appriciated...