Windows 7: unsigned drivers

Hello ,I have been using a kensington expert mouse on win 7 64bit ,and i have just tried out the kensington beta trackball works for Windows 7 64 bit, it works great ,apart from the driver not being signed by MS,I have found that by pressing f8 and allowing windows to work with unsigned drivers the program is fine ,untill i reboot!!! when if I allow win to load normally it does not see the expert mouse ,if I reboot again and use the f8 trick it works fine .this is a bit boring to have to do every time i start my pc ,so can any clever person tel me a way to work with a unsigned driver that will allow me continued use of the trackballworks ,by the way trackballworks betea 32 bit works fine with my 32 bit vers of win 7
many thanks for any help you can give
peter

There are permanent ways but it requires a little tweaking.
Here's the top result off google so I'm assuming it's one of the better methods.
How to Install & use unsigned drivers in Windows Vista/7 x64 - TechSpot OpenBoards