I solved my issue with this.
It says that it does not work with Win 7 x64, but it worked just fine for me.
Disable User Account Control (UAC) and reboot;
Go to Start and type cmd in the search box;
Right-click on cmd.exe (should be at the top of the list) and select Run as administrator;
In the newly created command prompt box, type the following (pressing enter after each line):
bcdedit /set testsigning on
bcdedit /set loadoptions DDISABLE_INTEGRITY_CHECKS
Note: DDISABLE is NOT a typo!
Install the problematic driver and reboot;
Your driver should now load successfully and you may now enable UAC!