I mostly followed this article to update a WSL version, except that I didn’t enable Hyper-V until then and got an error Please enable the Virtual Machine Platform Windows feature and ensure virtualization is enabled in the BIOS. while I was trying to update the vesrion.

These are steps I did to update the WSL version.

1. Ran PowerShell as Administrator.

2. Enabled the Windows Subsystem for Linux by next command.

   PS C:\Windows\system32> dism.exe /online /enable-feature /featurename:Microsoft-Windows-Subsystem-Linux /all /norestart
   Deployment Image Servicing and Management tool
   Version: 10.0.19041.844
   
   Image Version: 10.0.19042.868
   
   Enabling feature(s)
   [==========================100.0%==========================]
   The operation completed successfully.

3. Enabled Virtual Machine Feature by next command.

   PS C:\Windows\system32> dism.exe /online /enable-feature /featurename:VirtualMachinePlatform /all /norestart
   
   Deployment Image Servicing and Management tool
   Version: 10.0.19041.844
   
   Image Version: 10.0.19042.868
   
   Enabling feature(s)
   [==========================100.0%==========================]
   The operation completed successfully.

4. Tried to set the default vesrion of WSL to 2 and got an error.

   PS C:\Windows\system32> wsl --set-default-version 2
   Please enable the Virtual Machine Platform Windows feature and ensure virtualization is enabled in the BIOS.
   For information please visit https://aka.ms/wsl2-install

5. Checked if Hypber-V was enabled on my machine.

   In order to use WSL 2 on Windows 10, a CPU has to support Hyper-V. We can check whether CPU enables it or not on the result of msinfo32, which I found on this article. My result was

   • Hyper-V - VM Monitor Mode Extensions: Yes
   • Hyper-V - Second Level Address Translation Extensions: Yes
   • Hyper-V - Virtualization Enabled in Firmware: No
   • Hyper-V - Data Execution Protection: Yes

6. Enabled Hyper-V on a BIOS setting.

   Because my CPU was Ryzen 5, I followed this comment. So, I restarted my computer, went to Advanced Frequency Settings > Advanced CPU Settings and enabled on SVM mode. Then restarted my computer again.

7. Set default version of WSL to 2.

   Now it worked to me.

   PS C:\Windows\system32> wsl --set-default-version 2
   For information on key differences with WSL 2 please visit https://aka.ms/wsl2

8. Updated existing distribution to 2.

   I also updated Ubuntu which I installed before. We can check the version of installed distributions by wsl -l -v and can also update them by wsl --set-version [Name] [Version].

   PS C:\Windows\system32> wsl -l -v
     NAME            STATE           VERSION
     * Ubuntu          Running         1
       Ubuntu-20.04    Stopped         1
   PS C:\Windows\system32> wsl --set-version Ubuntu 2
   Conversion in progress, this may take a few minutes...
   For information on key differences with WSL 2 please visit https://aka.ms/wsl2
   Conversion complete.
   PS C:\Windows\system32> wsl -l -v
     NAME            STATE           VERSION
     * Ubuntu          Stopped         2
       Ubuntu-20.04    Stopped         1

Edited

On March 22, 2021 - Very slow network issue

I had an issue of very slow network on WSL 2 and I had to wait for a long time while I was using apt or git. After seeing this comment, I was able to solve the issue by disabling “Large Send Offload”. I did it on Device Manager > Network adapters > Hyper-V Virtual Ethernet Adapter > Properties > Advanced.