Windows 7 / PT8.0.3 doesn't recognize internal hdd

[scadh]

I recently finished building a new Windows 7 64-bit quad-core pc for a friend, for use exclusively to run Pro Tools.

I followed the instructions for using the 64-bit Windows 7 beta drivers w/ 8.0.3 and MBox 2, and everything installed and operates perfectly -- with one caveat. Pro Tools does not recognize the Audio drive, a 1 TB Western Digital. Oddly, Windows 7 recognized the drive during installation and subsequently listed it among the drives available for use in the "Computer Management" utility -- but it did not partition or format the drive during installation. I had to do so manually after installation was complete. I set the volume name to "Audio" and assigned it drive letter A:. The drive now works normally in all circumstances except with Pro Tools. Attempting to create a new session, it says "Pro Tools does not support unmapped network volumes". The thing is, it in an internal drive not a network drive. The machine is not even connected to a network or the internet, and the Ethernet port is disabled in the BIOS. The A: drive also does not show up in the Pro Tools media browser (or whatever it's called -- the window where you can drag any of the stock loops to the timeline). As a test, I created a temporary session on the system drive (C:, a ~360 gb Western Digital) and everything works fine.

I had started Pro Tools up one time before I realized that Windows 7 had not yet made the audio drive operations. I read online that that could cause issues, so I completely uninstalled Pro Tools and installed from scratch again in case it was a property file issue or something, but it didn't change anything. Perhaps there is a Pro Tools property file somewhere that contains a list of valid drives that didn't get deleted during uninstall?

I'm running out of ideas and would greatly appreciate any suggestions. Thanks!