When I upgraded my Surface PRO 2 from 8.1 to 10, the mini DisplayPort would not work. I verified that Windows 10, drivers and firmware were all up to date. With help from MS service, the following worked:

  1. To open Device Manager, click Start, click Search programs and files, and then type Device Manager. A list of available matching items appears above the search box; click Device Manager. Device Manager opens with your computer name at the top and a list of devices that are installed on your computer beneath your computer name.
  2. Locate the malfunctioning device in the list of devices, right-click the device, and then click Uninstall. When a warning message appears that you are uninstalling a device from your system, click OK. Device manager uninstalls the device.
  3. Right-click your computer name in Device Manager and click Scan for hardware changes. Device manager scans your system and automatically reinstalls your device.
  5. Right-click the device and click Properties. On the General tab of the device Properties dialog box, in Device status, you should see the message This device is working properly.

Note that originally, I followed thru Step 2 and then did an Install from the Device Manager menu and this failed. I tried several times. However, Step 3 above "Scan for hardware changes" worked.

Other than that, the upgrade was seamless, with a few quirks, having to get used to a new interface plus MS Edge. I like IE just fine but now it seems to fail frequently when Edge is also active. I am one who liked Windows 8.1 just fine. Hopefully, I will like Windows 10 once I get used to it. Also, RoboForm will not work with MS Edge (Ugh!).