There are two reasons for your drive not being seen by the computer .

If your drive has the U3 software on it contact the lead Teachers for support if not then try this...

Use the START menu to select Control Panel. Double-click Performance and Maintenance (or click Administrative Tools if you use Classic View).. Double-click Computer Management. Then click Disk Management on the left. Scroll through the various drives listed in the lower right. Right-click on the Removable Drive icon and select Change Drive Letter and Paths. Click Add. Click Assign the following drive letter if it is not already selected. Select a drive letter. It is recommended that 'Z' or another letter from the end of the alphabet be selected to assure it doesn't conflict with the standard drive letters (A:, C:, D:, E:, F: etc.) assigned sequentially from the beginning of the alphabet. Click OK. Close any remaining windows.