UEFI (Unified Extensible Firmware Interface) is a standard firmware interface for PCs, designed to replace legacy BIOS (basic input/output system). Many new computers are shipping with UEFI firmware instead of standard BIOS. Most of UEFI-based computers come with 64-bit UEFI but there are also some Windows 8 tablets that use 32-bit UEFI, such as Dell Venue 8/11 Pro, Toshiba Encore, Acer Iconia W3/W4, Lenovo MIIX 2, Lenovo ThinkPad Tablet 2 and ASUS Transformer Book T100/T300.
However, there is a limitation on installing Windows on devices with UEFI firmware. A 32-bit UEFI firmware core must be used to install a 32-bit OS and likewise 64-bit UEFI for a 64-bit OS. It is possible to have support for both 32-bit and 64-bit UEFI in one BIOS, but it requires additional work and ROM space, so this may not be commonly implemented.
If you forgot Windows administrator password for a UEFI-based computer, you can reset it easily with PCUnlocker. Just make a PCUnlocker Live CD and you can then use it to reset lost Windows password on any computer with EFI/UEFI/BIOS firmware. If your computer doesn’t have an optical drive, you can use the freeware ISO2Disc to make a GPT bootable USB drive from PCUnlocker ISO image.
PCUnlocker is available in two version (UEFI 64-bit version and UEFI 32-bit version). You can purchase the full version or try the trial version before deciding on making a purchase.
Download PCUnlocker with 64-bit UEFI Support
Download PCUnlocker with 32-bit UEFI Support