Tablet BIOS (UEFI) won't accept boot from USB
Try Switching off UEFI and change to 'Compatibility" mode in the BIOS to see if it helps.(This may slow the boot of Windows unfortunately)
If not try this link which may help. https://help.ubuntu.com/community/UEFI
Good luck and ask for more help if necessary
I'm glad you got it. As far as wubi goes (for anyone taking a look at this): Wubi will not work will not work along side Windows 8 (which I assume you were using) as long as the system is a UEFI system.
For more information you can check out https://wiki.ubuntu.com/WubiGuide