Safe Mode only run the most basic drivers and services and required Windows programs and offers basic functions for troubleshooting. Safe Mode with Networking only has the same feature, but also plus networking support.
How to Boot Up Windows 8 into Safe Mode With Networking on Surface Pro
* Immediately after you power the tablet, hold down the Shift key and repeatedly hit the F8 key to boot into the new recovery mode. If the Windows 8 is running, press Windows + C, click Setting > Power > hold down Shift from keyboard and click Restart.
* Click on “See advanced repair options Button” > select the “Troubleshoot” option in “Choose an option” screen > Click on the “Advanced Options” > Startup Settings > Click on Restart button in the screen.
* Surface Pro will reboot into Startup Setting screen. Press the number 5 on your keyboard to choose “Enable Safe Mode with Networking” from the lists, or use the arrow keys to highlight the option and press Enter.