Set-Theme : The term 'Set-Theme' is not recognized as the name of a cmdlet, function, script file, or operable program.

[JanDeDobbeleer]

Set-Theme : The term 'Set-Theme' is not recognized as the name of a cmdlet, function, script file, or operable
program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again.
At C:\Users\HP\Documents\WindowsPowerShell\Microsoft.PowerShell_profile.ps1:3 char:1

• Set-Theme Paradox

•   + CategoryInfo          : ObjectNotFound: (Set-Theme:String) [], CommandNotFoundException
    + FullyQualifiedErrorId : CommandNotFoundException
  

[JanDeDobbeleer]

You need to migrate V2 to V3 using the following guide.

The quick fix is to replace Set-Theme with Set-PoshPrompt, but it's advised to read the guide.

[blQSheep]

Thank you! i went trough the given guide and it works.
The windows documentation also has been updated now.

[patridge]

For anyone else who runs into this issue and misinterprets what this answer is suggesting, Set-PoshPrompt seems to be the new theme command going forward. You may not have had V2 installed, but whatever reference you were using had Set-Theme, which is the older command. Switching to Set-PoshPrompt will likely work going forward, but the guide will include any other changes that may affect the guide you are using.

When I found this discussion while trying to fix the same issue, I thought it was suggesting I somehow had oh-my-posh V2 installed without knowing it. At that point, I thought you were suggesting that Set-PoshPrompt was some backwards-compatibility legacy workaround command and Set-Theme would start working again after following the migration guide. That seems to be completely wrong and Set-PoshPrompt is the correct command going forward for all folks. The suggestion to read the guide is simply so you know about all the possibly related changes to V3 that you might encounter when following along with older guides.

[mahiuddin-dev]

You need to migrate V2 to V3 using the following guide.

The quick fix is to replace Set-Theme with Set-PoshPrompt, but it's advised to read the guide.
Thanks a lot