## The problem
After npm i -g firebase-tools on Windows, running firebase in the VS Code PowerShell terminal failed with: firebase : File [HOME]\... cannot be loaded because running scripts is disabled on this system. The same commands worked in cmd. npm had generated a firebase.ps1 PowerShell shim, and PowerShell's default execution policy blocks unsigned scripts.
## What fixed it
This is PowerShell's script execution policy, not a Firebase bug — npm's firebase.ps1 shim is blocked. Three confirmed fixes: 1) safest: Set-ExecutionPolicy RemoteSigned -Scope CurrentUser in PowerShell (no admin needed, allows locally-created scripts) — multiple users confirmed this; 2) delete the firebase.ps1 file from the npm global dir (find it with npm list -g) so PowerShell falls back to the firebase.cmd shim — also widely confirmed; 3) just use cmd instead of PowerShell. Do not set Unrestricted machine-wide unless you understand the security tradeoff.