Do you have already tried all drivers inside my package ? I hope that you install them so :
Right click and select Update Device Driver Software.
Select Browse my computer for driver software.
Select Let me pick from a list of drivers installed on my computer.
Select Show all and click next.
Click Have Disk, then Browse.
Go to your extracted folder and go into it, until a file called (android_winusb.inf ... for example) is there. Double click that.
Click OK and then Next (If it says not signed, just click next anyway).
Wait and if it says not signed, click install drivers anyway.
If all drivers will don't work ... it's a big problem difficult to solve.
However, my last suggestion is the next below (but I'm not sure that it will help you).
You can try to download & install install "SRS One Click Android Root v4.7" (exe for Windows).
At the left of the panel (of SRS One Click) click on "ADB toolbox" and then click "Reboot Recovery" in the right of the panel ... and see what happens.
[Only registered and activated users can see links Click here to register]
Please keep me up to date.