[Q] Cannot seem to access android devices on this pc topic

I have 5 devices here, Asus MeMo Pad ME170c, Lenovo 3500-fl, Archos Gamepad, HTC Desire HD and a cheapo generic chinese AllWinner a13. I cannot seem to get any of them to work on this pc. I cannot access them via adb nor browse the files on them via windows. Both the Asus and Lenovo are running KitKat 4.4.2 and connect up and under adb show as unauthorized, but I never get the authorization prompt on the devices. They show up under My PC where upon trying to access internal storage the window locks up/stops responding and the progress bar at the top fills up and gradually gets slower and slower until it's almost finished but then just carries on forever. I can never access the files. On my other pc I can access the files and get the authorization promp. Both pcs are running the exact same copy of windows 8.1 (installed from the same disk), are up to date and are both running the same usb drivers. So why can't I access the devices from this (my main) pc. The other devices are running older versions of android so I don't need to authorize the computer on these. They periodically show up as 'device' under adb but i cannot access their files as they show up as a removable device and when trying to access them windows says 'no media in the drive'.

I've done everything the same on both machines, the only difference is their hardware so I am wondering if there is anything hardware related that could be causing this problem. Could it be something to do with the motherboard?

The pc I can't access the devices with has an Asrock Z77 Pro4-M motherboard.

Does anyone have any suggestions on what could be going wrong here?

Cheers

Fraz.