Friend downloaded and installed Windows 10TP, not sure of the build. The machine is a Sony Vaio Tap-11 Tablet, Model SVT 112A2WL originally purchased running Win8. I have a feeling that windows 10 was installed over Windows 8 somehow. The tablet will not boot into windows at all. Receive error message: "Operating System Not Found". I used the built-in "Assist"button located on the back of the tablet. Tried all of the scenarios recommended by the MFR with negative results. The tablet has a USB port which i was able to use for an external drive hoping that maybe i could boot into an ISO file of Win10TP that i made previously on a DVD. Negative results. I am unable to even get a good command prompt for further troubleshooting. Any ideas out there. Cheers and beers