Assigning a permanent drive letter to your flash drive prevents Windows from changing its location each time you plug it into your computer. Windows normally assigns drive letters dynamically, meaning you might get a different letter based on the number of other drives in use. When you assign a static drive letter, Windows recognizes the flash drive and keeps it at the same drive letter, as long as that letter isn't already in use.
Plug your flash drive into your computer.
Press "Ctrl-X," and then select "Disk Management" from the options. In versions prior to Windows 8, press "Windows-R," enter "compmgmt.msc" (without quotes) into the Run dialog box, and then press "Enter."
Right-click the flash drive in the Disk Management window and select "Change Drive Letter and Paths."
Click the "Change" button, and then select the letter you want to use as the permanent drive letter. To ensure that Windows doesn't assign the letter to another temporary drive while the flash drive's unplugged, choose a letter toward the middle or end of the alphabet.
Click "OK," and then click "Yes" twice to dismiss the standard warning messages.
If the flash drive already uses the letter you want to assign as its permanent drive letter, you must reassign the letter to make it permanent: temporarily assign the drive to a new letter, restart the Disk Management applet, and then change the drive back to the original letter.
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