PREVENT AND FIX COPYING PROBLEMS
Scan your USB sticks for problems
Before you save important files to a USB stick, it’s wise to check that the device is working correctly to ensure data is transferred successfully and remains uncorrupted and readable.
Windows provides its own tool for checking removable drives for errors. Right-click your USB stick in File Explorer’s ‘This PC’ section, select Properties, and click the Tools tab. Click the Check button (see screenshot, right), then ‘Scan and repair drive’. The tool may tell you the drive doesn’t need to be scanned, but you can proceed anyway. If Windows finds any errors, it will attempt to fix them.
It’s also advisable to scan a stick for malware before you save anything to it, both to protect your data and to avoid infecting the next computer you plug the device into. Right-click the USB drive again and choose ‘Scan with Microsoft Defender’. Windows’ built-in security tool will then check the stick for viruses and other threats, and display the results within a minute or two. If you use third-party antivirus software, select the option in the right-click menu to scan with that instead.
Discover the actual size of your USB stick
Many cheap USB sticks with impressivesounding capacities, usually around 1TB or more, are actually fakes that offer nowhere near their claimed amount of storage. This can result in files you copy to them becoming corrupted because there’s not enough available room. Even if Windows says your device has plenty of free space, it may be accepting the fake claim, so it’s worth checking the actual size of your stick before you transfer any content.
One way of checking the actual capacity of your USB is with the free MediaTester tool ( www.tinyurl.com/2bcuc7xz).
Download the files, launch the program and click the two-dot Browse button next to the Target box. Select your USB stick, click OK and choose ‘Write and Verify’. The program will then copy test data to your device until it reaches the reported capacity to see how much space is really available.
MediaTester will abandon the test as soon as it detects an error, which indicates that the manufacturer of your USB stick is making a false claim about the amount of storage. If the test completes without any errors, then your USB stick is genuine. This may take up to a couple of hours, depending on the size of the drive, but to save time you can click Abort Operation (see screenshot above) once a large portion of data has been verified.
For the best results, MediaTester recommends you test an empty device, but it will still work on USB sticks that contain files and, unlike some rival tools, it won’t overwrite the data on them.
Remove write protection from your stick
When you try to copy files to a USB stick, you may sometimes see the error message: ‘ This disk is write-protected. Remove the write protection or use another disk’. There are several potential causes of this problem, but it’s usually possible to fix it relatively easily.
You should first check if a mechanical switch on the device is set to Write Only mode. This is designed to protect your data but also stops you from transferring anymore, so turn it off temporarily before copying files.
Next, right-click your USB stick in the This PC section of File Explorer, choose Properties and, on the General tab, make sure there’s enough free space for new files. Also click the Security tab and, in the ‘ Permissions for everyone’ section, ensure there’s a tick next to Write in the Allow column. If not, click Edit and tick the box there.
If everything looks as it should, try removing write protection by disabling ‘read-only mode’ in Command Prompt. Type cmd in the Windows search box and click ‘ Run as administrator’ under Command Prompt.
When Command Prompt opens, type diskpart ( 1 in our screenshot) and press Enter, then list disk 2 and press Enter again. This will list all the disk drives currently connected to your computer. Note the number of your USB stick and type select disk followed by that number, for example, select disk 2 3 . Press Enter, type attributes disk clear
readonly 4 and press Enter again. This should disable your USB stick’s read-only settings, allowing you to copy files to the drive. As a last resort, you can format the USB stick to make it usable again, but this will wipe all the data currently stored on it—see the box on page 45 for more advice on formatting.