Shell berks is not currently supported on windows 7

I got the following error:

PS C:\Users\jyu\Google Drive\Chef Learning\starter_kit\avery-chef-new-skijrwulpurzjp84> chef shell-init berks upload
Shell `berks’ is not currently supported
Supported shells are: bash fish zsh sh powershell posh
PS C:\Users\jyu\Google Drive\Chef Learning\starter_kit\avery-chef-new-skijrwulpurzjp84>

Shouldn’t it be two commands like:

chef shell-init powershell
berks upload

?

Yes, First you run the chef shell-init then run the berks upload