External hard drive - Can't record to it?

I'm pretty new at trying to use Studio One or the Capture that came with the Studio Live 16.4.2, but in both cases, when I have my project selected to point to the external hard drive, it won't allow me to record to it... Am I missing something, or is this really not allowed?

I have a USB2 hard drive connected to a laptop with USB2 ports running Window Vista.

???

Nevermind, was a freaky drive issue.