Help Can I flash a custom ROM in a tablet, overcaming bootloader?

[TronFourtyTwo]

Hello! I have a tablet whit locked bootloader, so I can't install a custom ROM using recovery, and others. Can I simply flash the new ROM (losing all the datas)? This will overwrite the existing bootloader? The bootloader, if not overwrote, will boot the new ROM? Thanks
EDIT: If after that the tablet won't boot, can I reflash a previous Nandroid backup to restore the tablet to the original state?

 

[scary alien]

Nope, the locked bootloader prevents any overwriting of any of the partitions on your device.

There are exceptions where some key partitions (/recovery, /system) can be set to read-write so that a custom recovery can be installed or the system partition replaced, but that is pretty rare nowadays.