I was struggling with getting the drivers for my Galaxy Nexus Fastboot protocol installed on Windows 8. On Windows 7, the supplied CAT files worked fine with a manual install. On Windows 8, I was getting "hash check" errors. Very frustrating. Luckily, I figured out how to turn off these driver verification checks. In order to do this, you must enter the following commands in command prompt (run as administrator) Code: bcdedit -set loadoptions DISABLE_INTEGRITY_CHECKS bcdedit -set TESTSIGNING ON then reboot. Please keep in mind that this MAKES YOU VULNERABLE to malicious drivers, packages, blah, blah, blah. Once you've installed the drivers you've been having trouble with, you can turn it off with these commands using the same process. Code: bcdedit -set loadoptions ENABLE_INTEGRITY_CHECKS bcdedit -set TESTSIGNING OFF Worked great for my proprietary SSL VPN software as well as Android drivers.