I have ASN, REX, PFPX, FSC, PRO ATC, FSP, VA INTERFACE FOR FMC 777 & 737 with pmdg 777,737 and 747 installed. I have this disconnecting problem even i dont do alt+tab. At first i thought this was due to my usb connection being loose.. i disconnected my logitech attack 3 joystick and plugged in with my gamepad with analog lights on to see if this is a connection problem. When i fly almost an hour without touching it disconnects. I seriously dont know whats the problem. i use windows 8.1. Can anyone help me out please?