Because in your post is written : Flash from Windows with Included Flash Utility. Flash original bios at first ! For Slic 2.1 use Marker tools included : T400-TP-7U.zip - for version 3.23(7UET93WW) T400-TP-7V.zip - for version 3.24(7VET94WW) Make a bootable flash. Copy the contents of the msrker's archive. Boot to pure DOS then run setmark.bat I tried to flash original BIOS at first with this error. And also when I tried to flash with "3.23(7UET93WW)_Wlisted" the same error Driver loading failed. The utility cannot proceed.". Thank you for your interest and sorry for my bad English.
What Windows you have installed? x86 or x64 ? for "x64" - run WinPhlash64.exe as Administrator (right mouse click on this file and choose "as Administrator")