How dangerous is it to update the bios. Jan 17, · Do not update your BIOS unless you must to resolve a hardware issue, such as updating a Z/ H/ B 100 series chipset to work with Kaby Lake. Although the BIOS was released a couple of years ago, it' s new to my pc as I' ve never updated BIOS before. Apr 16, · Have a Dell desktop, XPS 8900.A Flash BIOS upgrade runs the risk of making a board unbootable. A lot of time the anti virus causes them to fail. You copy the BIOS file to a USB drive, reboot your computer, and then enter the BIOS or UEFI screen.