Install Windows 7 on MacMini Server 0x80300024

I have a MacMini Server running Lion - latest updates.

It has two internal hard drives.

One hard drive will be formatted with Lion, the other with Windows Professional 7 SP1.

(no partitioning)

I used Boot Camp to create a Windows Installer on an attached USB drive using a Windows 7 Pro with SP1 ISO image.

Boot Camp begins the Windows install process.

I am prompted to Select Disk 0 Partition 2 BOOTCAMP, and format it with NTFS.

After doing so, I get the "Windows is unable to install to the selected location. Error: 0x80300024."

After Googling I see this is because Windows doesn't like additional drives attached.

Basically people are recommending either removing other drives or erasing other drives.

Neither of these options works, because the other drive is what has Lion and Boot Camp on it.

I wouldn't mind erasing it, as there is no end user data on it yet, but then how could I run Boot Camp to install Windows?

Is it possible to erase or remove the internal disk with Lion on it and boot from that USB drive without the aid of Lion/Boot Camp?

Suggestions?