Dell Venue 11 Pro 5130 cannot update the 64-bit BIOS

The Z3770 is a 64-bit processor, and you can see on CPU-Z that this CPU has a 64-bit instruction set ,I tried many ways to install a 64-bit system, but nothing worked ,Later I found out that this was a limitation from BIOS (only 32 bits),Now Dell has updated the Venue 11 Pro's 64-bit BIOS and show that it is compatible with the 32-bit Venue 11 Pro,But when I tried to install it, IT didn't work, (32-bit BIOS can be installed), Maybe very few people are using this tablet now

I'm sorry my English is not so good