The U drive is a Law School network drive, pretending to be a hard drive on your computer. When you're connected to your U drive, it appears in the list of drives on your computer as if it was another hard drive or floppy drive. Double-click My Computer to view your list of drives.
Floppy disks are notoriously unreliable, due to their sensitivity to magnetic and electrical interference. The U drive is a great alternative. If you save files on your U drive, whether from your laptop or from any of the lab computers, the files will reappear there when you log in again, even if you switch computers. Files you store on the U drive are virus-checked and backed up on School of Law servers every night.
If you are using a computer lab machine, you are automatically connected to your U drive. If you are using any other computer on campus (e.g., your personal laptop), you should see "How Do I Connect My Laptop to the U Drive?" in the Laptop section of the LCS website.
ADVANCED: Your U drive is actually a shared folder on a School of Law server (Themis), mapped as a network drive using the letter U. Each shared folder on Themis is named using a user's login and then shared only to that user's account (and the Themis administrator accounts). The computer lab login script automatically connects anyone who uses the lab machines to their Themis share, but laptop users have to connect manually.