What you really want is a bootable USB stick or external HDD with Windows on it and make every machine boot from that.
Windows has a Primary Partition where the OS
and the user files reside. "Desktop" is a location inside that partition. Usually at C:\Users\your designate\Desktop. By having Windows on a bootable USB stick or external HDD you retain the reference to Desktop
in context so as to make it usable.
Otherwise you need to mod every machine you come in contact with to reference Desktop on an "ad hoc" partition, which might have a differing designation depending on the machine and how many drives are installed and in what order.
For example: on my laptop C=Windows (internal HDD), D=DVD R/W drive (a physical device or DVD tray), E=Virtual CloneDrive (a virtualized DVD "tray" for playing disk images stored on C) and if I plug in an SD card to the slot it mounts as F. However, If I first plug in a device like a phone it mounts as F and then I when I next add an SD card it would mount as G...
So you see part of the difficulty is that the volume "SD card" may mount as a different designation depending on the pre-assigned, dedicated hardware/software bits which can vary from machine to machine. My wife's laptop is identical to mine except that she does not use Virtual CloneDrive so she has E available for the first ad hoc plug in... Similarly, your laptop likely has a D drive which is a physical tray for reading optical disks. It is doubtful to me that your tablet has a corresponding D drive so immediately you are out of sync for the Partition label. Even if you are diligent in making the "Desktop SD" the same designated drive letter on the same machine each time you add it, there would likely be disparity between machines.
To counteract that, you could use a consistent lettering system across machines by creating an arbitrary volume label far enough down the alphabet to make it assured that no machine you use this "Desktop SD" on would already have assigned the letter. So you either force every machine to mount the card as "Q" or you must exercise diligence in remembering the letter assigned to the removable "Desktop SD" upon insertion and make sure it is mounted at that point in the order each and every time on each and every machine.
Desktop is a file read by Windows Explorer. Now you have to mod each and every machine to have Windows Explorer pull Desktop from the correct path which you no longer wish to be C:\Users\your designate\Desktop, but rather Q:\Desktop or a floating designation if you cannot force every machine to mount the "Desktop SD" as Q...
This, sir, is a
LOT of work. I cannot tell you the specifics of making it happen. It does sound semi-feasible as I can imagine the mechanics even if I can't do the actual mods without tons of research and quite possibly much trial and error.
I understand that what you want is the same look and data to Desktop across every device upon boot. The better solution would be to use a portable, bootable Windows install that is your one and only copy that you use and to treat every machine as a dumb terminal that you plug into.
I suggest you look at PC sticks or, better yet, something like
the Kangaroo.