How to Fix an Unknown Partition

By Lee Prangnell

If you have a disk partition for which you do not know the drive letter, you can find the drive letter via the Microsoft Windows explorer. Once you have identified the drive letter for the defective disk partition, you can repair it by using the free and comprehensive Microsoft Chkdsk utility, which is part of the Microsoft Windows operating system. This is a command-line program, so you need to launch the Command Prompt to run it.

Click on the Windows "Start" button then click on "Computer." This will open a new window in which you will be able to see a list a of disk drives and partitions.

Identify the drive letter of the defective partition. Typically, your main system hard disk drive will use the letter "C," your CD/DVD drive will be letter "D," and all other disk drives and partitions will be in alphabetical order. (For this article, we shall assume that the "unknown" partition is drive letter "E." This is important in Step 4.)

Click on the Windows "Start" button, type "command prompt" in the "Search" field. Click on the "Command Prompt" option, at the top of the search results. This will open a Windows Command Prompt window.

Type "chkdsk e: /f /r" (without the quotation marks) and press "Enter" on your keyboard. Wait for the process to complete. This will check the partition for errors. If any errors are found, they will be repaired.

Restart your computer.