You need the VCOM Drivers. You can get them here: http://www.mediafire.com/file/6n78jodk7ld3aef/MT65xx+USB+VCOM+DRIVERS.zip
Your Device should get recognized as MediaThek Preloader. It doesn't work if it's not.
When you extracted the zip install the drivers via the exe file. After you did this you have to go to the device manager and add a new legacy hardware. Then you choose "install hardware manually from list" --> "show all devices" --> have disk. Now you choose the right folder for your system, that you extracted from the zip file, should be win7 I guess (for win7,8 and 10). I chose the MDMCPQ.inf. Now you should get a selection of drivers. You choose the PreLoader USB VCOM Port driver. After you installed it try again and tell me if this worked or if you even did this before.