Using the CMD prompt in Windows 10 or 11, it is a one-line request to get the serial number of a USB flash drive. The serial number in question is the device serial number, which follows the device and remains the same value used to identify the physical device. This serial number is written into read-only memory on the flash drive and cannot be duplicated, deleted, or modified. This is different than the volume serial number, which we covered in a previous post.

Steps are very simple:

# Insert a flash drive (or multiple drives)

# Select a flash drive by clicking on the drive letter

# In the Explorer path field type cmd

This will open the Command Prompt.

# Copy the text below and press Enter

wmic path Win32_USBControllerDevice get Dependent | find “USBSTOR”

This command asks Windows to search the system for any Mass Storage devices (flash drives) connected to the computer’s USB host controller.

You do need to parse some information out, because more than just the serial number is returned.

The serial number of the USB flash drive is listed last, and there is a &0 at the end which is not part of the serial number. The hardware serial number can vary in length, so there is no fixed guideline. In practice, we commonly see serial numbers ranging from 8 to 30 alphanumeric characters.

Using a third-party utility, you can confirm that the serial number reported by the software matches the same serial number shown by the CMD prompt method.

1. Can you freeze a USB flash drive?
2. Will a USB flash drive survive the washing machine?
3. Can a USB flash drive survive getting wet?
4. How long does a USB flash drive last?
5. Why is a USB flash drive so durable?

#1 – Can you freeze a USB flash drive?

Yes. If a USB drive is frozen, it will work and will typically function immediately without the need to defrost. Nerdy details below.

#2 – Will a USB flash drive survive the washing machine?

Yes, a USB flash drive will usually survive a washing machine cycle; however, it is recommended to let the flash drive dry for 24 hours before attempting to use it. Nerdy details below.

#3 – Can a USB flash drive survive getting wet?

Yes, a USB flash drive can survive getting wet; however, it is recommended to let the flash drive dry for 24 hours before trying to use it. Nerdy details below.

#4 – How long does a USB flash drive last?

Data on a USB flash drive could last indefinitely if configured correctly and stored under proper conditions. However, the real-world answer depends on several variables: the type of NAND flash memory (SLC, MLC, or TLC) and how the device is stored over time. The technical details are below, but the practical guidance is simple: (A) write protect the device once data is finalized, and (B) avoid exposing it to extreme temperatures and harsh environments.

#5 – Why is a USB flash drive so durable?

A USB flash drive (thumb drive) uses NAND flash memory. The key characteristic of NAND memory is its ability to retain data without continuous power.

The technical (nerdy) details behind the answers above

Here is a quick recap of traditional storage memory. In simple terms, a computer uses long-term storage (historically hard drives) and short-term memory (RAM). Traditional hard drives store data magnetically on spinning platters, where positive and negative charge states represent binary ones and zeros. Because of this magnetic state, data remains intact even when power is removed.

RAM (Random Access Memory), by contrast, only holds data while power is flowing. Once power is turned off, the information in RAM disappears.

Together, long-term storage and RAM allow a computer to both save data and operate quickly.

Flash memory (NAND memory) is different. It is a non-volatile storage medium that does not require power to retain data. Flash memory is a type of electronically erasable programmable read-only memory (EEPROM).

You can think of it like a “dam” holding electrons in place so the stored data does not change when power is removed.

Because of this characteristic, the flash memory inside USB drives is very durable. A USB flash drive can survive being left in a freezing car overnight in North Dakota, survive a trip through the washing machine, or survive getting wet in the rain.

That said, flash memory does have a finite lifespan. NAND flash has a limited number of Program/Erase (P/E) cycles before it begins to lose integrity. Each time data is written or erased, the internal structure degrades slightly. Think of it like repeated small storms weakening a dam over time. Eventually, after enough cycles, the memory can fail.

The number of P/E cycles depends heavily on the type of flash memory used (SLC, MLC, or TLC), which we covered in detail in an earlier article.

Environmental factors generally do not impact NAND flash performance as much as people assume. However, temperature does matter for long-term data retention.

Technically, degradation occurs in the oxide layers that insulate the floating gate (the “dam”). As the oxide weakens over repeated use, electrons can begin to leak, which makes stored data less reliable. The device may continue to function, but with increasing risk of data corruption.

If the device is write protected, the P/E cycle count no longer increases. If data is written early in the life of the memory and the device is then write protected, data retention can be extremely strong. Cold temperatures do not accelerate data loss, while sustained high temperatures can accelerate degradation because heat increases the likelihood of charge leakage.

A “write protect switch” for a USB drive is meant to turn on and off the ability to write data to the drive. When the USB is locked (read-only) content cannot be added, changed, altered, manipulated, formatted or deleted off the drive. What is the point of a physical write protect switch if anyone can turn the write protection on or off? Doesn’t add up…

Yes, a write protect switch keeps the honest people honest, however the USB write protect switch doesn’t apply in all situations.

So what replaces a write protect switch for a USB flash drive?

How about programmable firmware for turning ON and OFF the USB write protection?

Better yet, how about a required password before turning ON and OFF the USB write protection?

We can relax because the Lock License USB flash drive addresses both these issues of
#1) Replacing the USB write protect switch with a more secure method
#2) Provides the feature of assigning a password to turn on and off the USB write protection.

The Lock License drive is a hardware based ( at the chip level ) write protection solution and through a specific vendor software command the write protection can be removed to make the USB stick writable. The function to write protect the media can be done through a provided GUI software application, can use a command line to change the write protect status, or use the command line to build your own custom method for how the USB write protection can work.

The write protection is configured on the USB controller of the flash drive. This means the write protection is done at the device level and will follow the USB stick. The result is a Lock License drive which is truly read-only when connected to anything… such as a Windows computer, Mac computer, Linux box, Smart TV, car stereo, anything!

The Lock License drive comes with a software method to unlock the drive and make it writable. This special software requires a password to be assigned for the unlocking. The password is required because the manufacturer, Nexcopy, didn’t want a universal way to unlock the drive.

Kanguru manufactures a USB flash drive with a physical write protect switch. The write protection itself is as secure as the Lock License solution, the difference is a Lock License drive adds one additional layer of security. The additional layer of security, the password requirement to make the stick ‘writable’ is an important step for ensuring the device is as secure as possible. To be clear, the Lock License drive is always readable. This product seems a great solution for those who want a USB write protected without the ability for users to turn the write protection off with a flip of a switch.

Another interesting fact about the Lock License drive is the default state of the USB stick being read-only, or write protected. This means it is impossible for a user to accidently leave the Lock License drive unlocked.

The “locking” or write protection is done when power is cut from the device. Even if a user forgets to lock the drive, the locking happens automatically when the USB is disconnected from the computer. This is a major issue with those using a USB write protect switch; if a user forgets to set the write protect switch, well not much security at that point.

It is worth noting there is no universal way to write protect any flash drive, this is why you cannot buy some software solution to do the feature. Write protection is a hardware based solution, not software.

From our on-line research, the Lock License drive is manufactured by Nexcopy Inc who is based out of Southern California. The product is available in USB 2.0 for the smaller 2GB and 4GB and any GB capacity higher (8GB and above) is USB 3.0 technology. The maximum size as of this posting is 256GB media.