As far as I can tell at one read, that method was popular and valid at one point and there was even a way to get rid of the "Test Mode" text in the lower right-hand corner of the desktop. That it still works I cannot say until I check it out against our own test results and previous methods that worked.
I strongly doubt it will work though as an application would long ago have been put together to make that easier than going through the whole process each time. There were two apps that did work and allowed one to create signed drivers, but they stopped functioning after the final release of Windows 7 RTM which was in June 2009 to Microsoft "Partners" and I think July 2009 to TechNet subscribers. The date of the article you point is March 2009.
Go to http://www.planetamd64.com
and check out there if there is a method...I doubt it very much. Don't worry about the AMD thing if you use an Intel system as these things are not CPU tied. You may have to register at planetamd64 to ask questions. They were at one time an affiliate site to us but we haven't had contact with them for a long time now. At one time they were very up to date on all things 64-Bit but I don't know how they fare these days.
Howz about emailing the vendor of the hardware/software you need 64-Bit drivers for?
Alternatively, will the software/hardware run on XP X64 which does not need driver signing? In that case try dual booting with XP 64 if you have a copy or can get one easily.
"The great majority of mankind are satisfied with appearances, as though they were realities, and are often more influenced by the things that seem than by those that are." - Niccolo Machiavelli