Cryptolocker. The encrypted files may be recoverable if there are shadow copies of them.
Aside from that, it really depends. Though it should only use a small percentage of space.
But if you really do wish to disable them, run "fsmgmt.msc" on the server, right click on "Shared Folders (Local)", open "All Tasks" and select "Configure Shadow Copies". From there you can disable them per drive.
Is this in "INF" format (inf, sys and cat files)?
If so, then are you familiar with DISM commands? If so, then you can integrate the drivers into the restore image direct and this may fix the issue.
Then it sounds like you're SOL.
Well, short of using some sort of activation hack, and hope that doesn't have issues...
That, and it still may be worth calling Microsoft, as they *may*, just *may* be able to help you out.