First-time installation fails on Windows due to registry key lookup error

[eakuefner]

pnpm version: 7.1.1

Code to reproduce the issue: iwr https://get.pnpm.io/install.ps1 -useb | iex

Expected behavior: pnpm is installed for the current user

Actual behavior: Fails with error

Downloading '@pnpm/win-x64' from 'npmjs.com' registry...

Extracting downloaded '7.1.1' archive...

Running setup...

C:\Users\eakuefner\AppData\Local\Temp\tmpF3B0.tmp.extracted\package\pnpm.exe
Copying pnpm CLI from C:\Users\eakuefner\AppData\Local\Temp\tmpF3B0.tmp.extracted\package\pnpm.exe to C:\Users\eakuefner\AppData\Local\pnpm\pnpm.exe
 ERROR  Command failed with exit code 1: C:\Windows\system32\reg.EXE query HKEY_CURRENT_USER\Environment /v PNPM_HOME
ERROR: The system was unable to find the specified registry key or value.

Additional information:

• node -v prints: This is a totally fresh setup without node.
• Windows, macOS, or Linux?: Windows

[IAALAI]

Do you have enough permissions?

[IAALAI]

I also had this problem at first and then adopted Corepack.

[zkochan]

It is a regression caused by #4731