Windows 10: NUL device is suddenly broken.

After upgrade to Win10 version 22H2, the NUL device suddenly is not working any more. I have many programs that do this to avoid the user's seeing File Not Found errors etc. The error is "Access is denied". This happens even when I'm admin. What did Microsoft do this time? How do I fix it?A simple example is something like "DIR > NUL". This has always worked before; now I get "Access is denied". I've googled and found many, many postings four years ago and more. Nothing about my specific problem, though.

:)

 

on Win10, XCOPY to >NUL takes 10 times longer than actual copy

XCOPY /E .\*.* >NULL

In a console environment "nul" is not a driver. It is a "nul device", i.e. a ficticious device to be used when the console output from a command should be discarded.

If you wish to perform speed tests then you should run them like so:

• Always specifiy a fully qualified source folder
• Always specifiy a fully qualified target folder.
• Use robocopy.exe to monitor progress. It is the recommended tool for system administrators.

Your command might then look like so:

robocopy /E C:\2017-V D:\Target *.*

Note also the misspelling of "NUL" in your command. "Null" is a valid file name.

 

KB4566782 has caused a problem creating a nul port that's needed for Papercut installs

It's no longer possible to create a nul port in Settings>Devices or in the print management snap in. Uninstalling this update resolves the problem. While there are a few backdoor methods to add the port, the correct way is broken. My Windows 10 Pro
2004 build is 19041.450.

 

Windows 10 Suddenly Starts to Lag

Hello,

For us to better assist you, we'd like to know the following:

• Confirm which build is currently installed on your device. To check, follow the steps below:

• Press Windows key + R, then type in winver.
• Click OK.

• Were there any recent changes made prior to this issue?
• Are you using any 3rd party antivirus program?

Meanwhile, we suggest performing the suggested steps on this article
on how to improve the performance of your Windows 10 device.

We look forward to your response.

Regards.