These days, all USB drives are plug-and-play with Windows XP: you plug it in, Windows recognizes it and shows it in the Explorer, usually with a drive letter like <c>F</c>, <c>G</c> or <c>H</c>. Sometimes, however, the auto-detection of the drive letter goes awry and the drive doesn't show up in the Explorer and you're hard-pressed to access it.<fn> If this has happened to you, you should first verify a few things: <ul> Make sure that the drive is plugged in properly and that it is turned on (and/or drawing power somehow, either through its own power adaptor or through the USB connection). Type <kbd>Windows-Key+Break</kbd> to show <i>System Properties</i>, then go to the <i>Hardware</i> tab and show the <i>Device Manager</i>. Is the drive visible there? If it is, you're in luck. </ul> In order to fix the problem, you'll have to assign the drive a new letter. <ol> From the <i>Control Panel</i>, select <i>Administrative Tools</i>, then select <i>Computer Management</i>. In this window, select <i>Disk Management</i> under <i>Storage</i>. On the right, you should see all of the hard disks attached to your computer as well as their partitions. Select your USB drive from the list and right-click, selecting <i>Change Drive Letter...</i> from the popup menu. From the resulting dialog, select a letter that doesn't conflict with an existing drive letter (make sure to avoid any letters used by network shares) and press <i>Ok</i>. </ol> Your drive should now appear in the Windows Explorer under the newly-assigned letter. <hr> <ft>This happened recently with a <a href="http://www.seagate.com/www/en-us/products/portable/freeagent_go/">FreeAgent(tm) Go</a> drive from Seagate, which failed to show up because Windows had assigned it the drive letter <c>H</c>, which was already mapped to a network share.</ft>