Command Prompt Disk Part/List Disk cannot find USB drive (Windows 7)

Hi everyone,

I have a Dell XPS laptop, which was working fine up until yesterday when this morning I got the black Windows Recovery screen telling me that Windows had failed to start. I went onto Startup Repair but this didn't work, and tried starting normally which just kept restarting my computer.

Luckily, I have a Windows 7 DVD, so I can reinstall with no problem -However I have lots of files that I really want to save.

I booted from the DVD and ran the command prompt so I could transfer my hard drive to my external USB drive (they're both about 250GB) before I reinstall Windows. I ran the Disk Part/List Disk command but it cannot detect my USB drive; it can only find the internal hard drive.

When I use another computer, it does detect my USB drive using List Disk, so I'm thinking that the USB drive is fine.

I read something about Windows XP not being able to detect removable media in this way, but shouldn't this work under 7? What am I doing wrong?

I am kicking myself for not backing up this data! Learn the hard way, I guess.

This site has helped me out a lot of times in the past so thanks for any help.