Win8.1 64bit USB mining problem

[CapnBDL]

Help!!! When trying to mine /w RedFury USB, my 64 bit Win8.1 system only does around 420Mh/s, yet when I plug it into my Win8.1 32bit laptop, it gets better than 2Gh/s. Obviously, I'm using the same software, etc. The laptop isn't made to run 24/7 tho. I've tried different miners, etc. too. Same results.  The computer even has the 3.0 USB, and I've tried everything. Can somebody tell me what gives?

I'm SO CONFUSED!!@!$%

Thanks!