Manage Learn to apply best practices and optimize your operations.

NirSoft DriveLetterView Shows Assigned Win10 Drive Letters

This morning, as I was reading through new or changed posts at, I saw mention of another great Nir Sofer tool. This one’s called DriveLetterView. That is, NirSoft DriveLetterView shows assigned Win10 drive letters. This applies to letters for drives actively mounted and accessible on a Win10 system right now. It also applies to letters assigned to drives previously mounted but neither present nor active. That status (Connected = “No”) usually applies to USB drives of some kind, often UFDs (USB Flash Drives). Here’s what the program’s output looks like on my production PC. It currently shows 10 (ten!) connected drives, and 5 disconnected ones.

I sorted the listings on the “Connected” column, so you see all ten connected drives at the top of the listing.
[Click image for full-sized view.]

What NirSoft DriveLetterView Shows Assigned Win10 Drive Letters Really Tells You

The disconnected drives appear with a question mark (?) at the upper right of their drive icons. If you look at their “Instance ID” fields, some are blank and some are occupied. The blank ones usually correspond to UFD drives, while the non-blank ones represent specific peripherals. The item for the A: drive clearly shows a floppy disk assignment: “USBSTOR\SFloppy…” The one that starts with “SCSI/CdRom…” shows that I attached my USB Blu-ray/DVD/CD player to this PC some time ago (P:). The item that starts with “USBSTOR…USB_DISK_3.0” is for one of my USB 3.0 SSD drive enclosures or caddies (Q:).

To check this assertion, I plugged in a UFD. Immediately the listing for Drive M changed to connected. The Instance ID string now reads
That tells me it recognizes the 16GB Mushkin Atom UFD I just plugged in. Good-oh!

What DriveLetterView Is Good For

I like this tool because it shows me which drive letters are occupied. I can also click on any drive letter, then click the red X delete symbol in the toolbar at top left, and delete that drive letter assignment. This makes it suitable for cleaning up after UFDs or removable drives I may no longer have or use. But the program is also pretty informative in and of itself. It provides device IDs normally accessible only through Device Manager, along with all kinds of other descriptive drive info. Check it out! I predict you’ll like — and use — it.