Upgrade to PowerShell 7

.ado/scripts/build.js

@@ -101,7 +101,7 @@ function ensureNuGet(toolsPath) {
   ensureDir(toolsPath);
   console.log(`Downloading nuget.exe to: ${localNuGet}`);
   execSync(
-    `powershell.exe -NoLogo -NoProfile -Command ` +
+    `pwsh.exe -NoLogo -NoProfile -Command ` +
       `"[Net.ServicePointManager]::SecurityProtocol = ` +
       `[Net.SecurityProtocolType]::Tls12; ` +
       `Invoke-WebRequest -Uri 'https://dist.nuget.org/win-x86-commandline/latest/nuget.exe' ` +

.ado/templates/yarn-install.yml

@@ -4,6 +4,10 @@ parameters:
   default: .
 
 steps:
+  - task: NuGetToolInstaller@1
+    inputs:
+      versionSpec: ">=5.8.0"
+
   - script: yarn --cwd ${{ parameters.workingDirectory }} install --immutable
     displayName: yarn install (immutable)
     retryCountOnTaskFailure: 2

change/@react-native-windows-cli-d0909d53-2984-4eff-bcf6-fe1702c03277.json

@@ -0,0 +1,7 @@
+{
+  "type": "prerelease",
+  "comment": "Upgrade to PowerShell 7",
+  "packageName": "@react-native-windows/cli",
+  "email": "julio.rocha@microsoft.com",
+  "dependentChangeType": "patch"
+}

change/react-native-windows-f8669931-74f3-4c8e-a1d1-ecb19860ee42.json

@@ -0,0 +1,7 @@
+{
+  "type": "prerelease",
+  "comment": "Upgrade to PowerShell 7",
+  "packageName": "react-native-windows",
+  "email": "julio.rocha@microsoft.com",
+  "dependentChangeType": "patch"
+}

packages/@react-native-windows/cli/src/utils/commandWithProgress.ts

@@ -4,7 +4,10 @@
  * @format
  */
 
-import {spawn, SpawnOptions} from 'child_process';
+import {execSync, spawn, SpawnOptions} from 'child_process';
+import fs from 'fs';
+import os from 'os';
+import path from 'path';
 import ora from 'ora';
 import spinners from 'cli-spinners';
 import chalk from 'chalk';
@@ -47,7 +50,47 @@ export function newSpinner(text: string) {
   return ora(options).start();
 }
 
-export const powershell = `${process.env.SystemRoot}\\System32\\WindowsPowerShell\\v1.0\\powershell.exe`;
+function getGlobalNuGetPackagesFolder(): string {
+  if (process.env.NUGET_PACKAGES) {
+    return process.env.NUGET_PACKAGES;
+  }
+  try {
+    const output = execSync('nuget locals global-packages -list', {
+      encoding: 'utf8',
+    }).trim();
+    const match = output.match(/global-packages:\s*(.+)/i);
+    if (match) {
+      return match[1].trim();
+    }
+  } catch {}
+  return path.join(os.homedir(), '.nuget', 'packages');
+}
+
+function findPwsh(): string {
+  const nugetPackages = getGlobalNuGetPackagesFolder();
+  const nugetPwsh = path.join(
+    nugetPackages,
+    'PowerShell.7.6.1',
+    'tools',
+    'net8.0',
+    'any',
+    'pwsh.exe',
+  );
+  if (fs.existsSync(nugetPwsh)) {
+    return nugetPwsh;
+  }
+
+  try {
+    const found = execSync('where pwsh.exe', {encoding: 'utf8'}).trim();
+    if (found) {
+      return found.split(/\r?\n/)[0];
+    }
+  } catch {}
+
+  return `${process.env.SystemRoot}\\System32\\WindowsPowerShell\\v1.0\\powershell.exe`;
+}
+
+export const powershell = findPwsh();
 
 export async function runPowerShellScriptFunction(
   taskDescription: string,