[Android Q&A, Help & Troubleshooting] Old faithful:
Well like the say in French... "Cordonnier mal chaussé" which means, loosely translated, that I get everyone's system working great while mine only gets fixed good enough to just do what I need it to do ;)

If is was my choice, I would only be running Windows 98SE on all my machines, the Windows 7 system can't run some of the software I use, I have some terrific software over 20 years old that was orgnally designed for Windows 3.1, unfortunately abandonned since then and that to this day has no modern equivalent and that's the main reason I've resisted 'upgrading'... At least these 16 bit programs work, with some limitations, under Vista (not at all under 7), and truly excel under XP... I told you I was an old timer!!!

You need the custom recovery to backup the NVRAM... The factory recovery doesn't. The NVRAM has the hardware info needed for proper operation with WiFi. If you made a bad flash and it was so bad you needed to reload the factory ROM by the format method, you would loose the NVRAM contents and would be in trouble if you had no NVRAM backup for any apps or accounts that check the MAC address and other unique identifiers contained therein.

You would install Supersu to gain SD Card access, as it is needed to edit the permissions file. Otherwise you would simply get "permission denied" and similar other error messages whenever you try to write onto it. Stock KitKat has basically rendered external SD Cards useless, so rooting it is a must in that regard.

As for backup, the factory recovery allows you to backup user data, but I haven't tried it. Anyway, it gets replaced whenever you flash the complete factory ROM though SP Flash, in which case you would simply have to get usb debugging activated again in the device after it was flashed so that you could push the update zip file onto the device though adb and then, through standard recovery, install that to get your system back in the exact condition you purchased it...

To sum up the rooting process:

- enable USB debugging in settings, about device, tapping build number 8 times, then enabling USB debugging

- on your pc with adb drivers loaded and the adb mini sdk installed, open a command line and adb push supersu.zip onto storage/sdcar0/supersu.zip

- shut down the tablet and disconnect

- have the SP_Drivers from this thread decompressed and ready

- have the carliv recovery package for the OS you are using decompressed and ready

- start SP Flash, in Download tab get the scatter file from the carliv recovery zip package

make sure only the recovery is ticked

- start Device Manager on the PC

- plug in the tablet. Device manager will refresh and show MT67xx vcom for just two seconds,

quickly right click it and select install driver manually, navigating to the CDC directory of the SP_Drivers directory

- disconnect the tablet

- in SP flash, click Download

- reconnect the tablet. Recovery will flash in a matter of seconds and you will get an OK.

- shut SP Flash down

- remove the tablet and make sure you do not start it, but get into recovery instead:

- press volume up and power and maintain that for about 10 seconds, past the vibration and the start of splash screen.

- a dark screen with very small characters shows up with three options: Recovery, Speedboot and Normal.

- don't touch anything and make sure you understand what the buttons do.

- volume up is used to navigate (go to Recovery), volume down immediately activates the selection.

DON'T select any other option! BTW, the power button has no effect.

- Carliv recovery will start. Select load package from sd card (sorry, can't remember the exact wording)

- select the supersu.zip you previously pushed by adb.

- load it, then return to the previous page to reboot.

- congratulations, you can now backup your NVRAM and now own your device!

Actually they made the SD Card accessible again in Lollipop... They must have received some very nasty protest letters, perhaps even threats of legal action from companies who had their tablets returned as defective because SD Cards couldn't be used with them anymore...

Actually I installed it just to see and it does exactly what the scrip does, nothing else. The GUI is just there for convivial reasons. After you've gained access, you can simply remove the app. Just remember it requires root to do its job.

Good choice :). And remember, if your SD Card is more than 32GB, you will need to reformat it as FAT32 before it can be seen by the device.