First and Foremost... This is FOR EDUCATIONAL PURPOSES ONLY! USE AT YOUR OWN RISK! I TAKE NO RESPONSIBILITY FOR ANY ISSUES THAT ARISE FROM THE USE OF THIS PROCEDURE. With that said, it works flawlessly on my Surface Pro. Second, I want to thank MetalDwarf for coming up with a solution to enable this on 64 bit versions of Windows 7 which can be found at hardforum.com. Fortunately, it also works on windows 8. I also want to thank the other websites and original authors of software and instructions that are mentioned elsewhere in this guide. It took me a while to figure out how to do this so I consolidated all the information into this one document to simplify the research. Direct downloads violate the forum guidelines Download the 64bit Hitachi Microdrive driver “cfadisk-x64-1.zip”. Download the Driver Signature Enforcement Override “dseo13b.exe” from NGHQ.com (It says it is only for up to Windows 7 but it does work on Windows 8) Download My_WCP_Watermark_Editor.exe Disable secure boot on the Surface Pro Perform this procedure as originally posted at surfacetablethelp.com "* First boot Surface to the UEFI Firmware Settings in Windows 8 “Advanced Options” UI. Open charms bar from start screen, tap Setting > Change PC settings > General, and then “Restart now” under Advanced startup. Tap on “Troubleshoot” in the “Choose an option” screen > Advanced options > UEFI Firmware Settings, and “Restart” button. You can also hold down the Volume Up key on the tablet during the initial stages at boot. * While Surface are booted directly to an all black screen with two options: Security Device Support, Secure Boot Control. Tap the space labeled [Enabled], next to Secure Boot Control, and select [Disabled] from pop up prompting. Then tap Exit Setup" Enable Loading of Unsigned Drivers run cmd.exe as the administrator Now type the following "bcdedit -set loadoptions DISABLE_INTEGRITY_CHECKS" (without the "") press Enter: "bcdedit -set TESTSIGNING ON" (without the "") press Enter: Note: this will create a permanent watermark on the desktop showing the Surface Pro in Test Mode. This watermark can easily be removed with My_WCP_Watermark_Editor.exe Editing and Installing the Unsigned Driver The below part is copied directly from MetalDwarf's post and all credit goes to him, however, I have added the specifics to accomplish this on the Surface Pro. Part A First you need to find the name of your USB or SDHC device run -> regedit -> navigate to: HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Enum\USBSTOR Right click on "Disk&Ven_Generic-&Prod_USB3.0_CRW__-SD&Rev_1.00" and click "copy key name" Part B unzip the files from " cfadisk-x64-1.zip " and open cfadisk.inf in notepad. scroll down to the section [cfadisk_device] you will see the line %Microdrive_devdesc% = cfadisk_install,IDE\DiskTS64GCF400__________________________ ____20101008 delete everything after the comma so you are left with %Microdrive_devdesc% = cfadisk_install, paste your device string you copied in Part A starting from USBSTOR into the line just after the comma, no spaces. you should have something that looks like this %Microdrive_devdesc% = cfadisk_install,USBSTOR\Disk&Ven_Generic-&Prod_USB3.0_CRW__-SD&Rev_1.0 repeat this process for the section immediately below called [cfadisk_device.NTamd64] If you are so inclined you can name your device at the bottom of the file by editing the text in the quotes in the last line after it says Microdrive_devdesc = "your device name here" save the file, you now have a functioning driver. Part C You now need to install the driver Open Device Manager, open Disk drives, right click on "SDXC Card" and chose to update driver. Click "Browse my computer for drivers software" then click "Let me pic from a list of device drivers on my computer." Now click "Have Disk" and open the .ini file you just edited. Windows will bitch and complain that the file is not signed, and not a compatible driver. Proceed anyways. Once installed you should see the USB device show up as a "Disk Drive" Sign the Newly Installed Driver and Remove Watermark Run dseo13b.exe as an administrator. Click Next, then Yes. Check "Sign a System File" and click Next. Enter the path to the newly installed driver and click OK. For me it was C:\Windows\System32\Drivers\cfadisk.sys Exit the program. Run My_WCP_Watermark_Editor.exe as an administrator. Check “Remove Watermark” at the top and click Apply Settings. Reboot the Surface Pro and you should see the SD Card listed beside the C Drive as a Hard Disk. The watermark should also be removed. Now you can move SkyDrive to the SD Card, install programs, create multiple partitions or whatever else you desire. Enjoy!