I have a Samsung Galaxy S3 SGH-T999 (running 4.3) that I have been using with Windows 7, XP, and Vista machines as a "media device" without Kies; I simply plug it in and use it as a drive. When plugged in to those machines, the phone says "connected as media device"... I recently replaced the 7 machine (Dell Optiplex 745) with a brand new Dell XPS8700 with Windows 8.1. However, when I connected the phone via USB, it was not recognized at all; the phone only charges. (FWIW, it does recognize my old iPhone 4). 1) I read that for some, installing Kies would load the latest drivers and solve the issue, so I began with Kies3 because even though my phone is pre-2013, it is running 4.3, so I figured that would supersede. I installed Kies3 and let it update itself to the newest version. Kies3 did not fix the problem, and did not recognize the device. 2) Next, I uninstalled Kies3, and installed Kies 2.6. All indications are that 2.6 is for 7 and XP, but I installed it anyway. It also updated itself. No change in device status, and also tried running the "troubleshoot connection error" tool, which also helped nothing. 3) I learned about the potential Windows media player and Windows 8.1n/kn issue and applied the pack, which stated that it did not apply to my windows version. 4) I checked device manager, and although I'm not 100% sure I've ID'd the correct device under USB controllers, there is one that says "unkown USB device (device descriptor failed)", which I suspect is it. 5) In the midst of these efforts, I also experimented with various cables and USB ports. FYI, the phone does still connect with the other machines, just not the 8.1 machine. Any other suggestions?