@@ -54,6 +54,9 @@ describe("embeddedScripts", () => {
   it.each([
     [`python3 -c 'print(1)'`, "python", "print(1)"],
     [`python3 -X dev -c 'print(1)'`, "python", "print(1)"],
+    [`py -3 -c 'print(1)'`, "python", "print(1)"],
+    [`C:\\Python312\\python.exe -c 'print(1)'`, "python", "print(1)"],
+    [`"C:\\Program Files\\Python312\\python.exe" -c 'print(1)'`, "python", "print(1)"],
     [`node --eval "process.exit(0)"`, "javascript", "process.exit(0)"],
     [`bun -e 'console.log(Bun.version)'`, "typescript", "console.log(Bun.version)"],
     [`deno eval 'console.log(1)'`, "typescript", "console.log(1)"],
 
@@ -262,11 +262,14 @@ function forEachCommand(
 }
 
 function programName(word: Word): string {
-  return (word.value.split(/[\\/]/u).at(-1) ?? "").toLowerCase().replace(/\.exe$/u, "");
+  // Bash reads `C:\Python312\python.exe` unquoted as escapes; Windows meant a path.
+  const path = /\\/u.test(word.text) ? word.text.replace(/^["']|["']$/gu, "") : word.value;
+  return (path.split(/[\\/]/u).at(-1) ?? "").toLowerCase().replace(/\.exe$/u, "");
 }
 
 function interpreterFor(name: string): Interpreter | undefined {
-  if (/^python(?:\d+(?:\.\d+)?)?$|^pypy3?$/u.test(name)) return PYTHON;
+  // `py` is the Windows Python launcher, as in `py -3 -c '…'`.
+  if (/^python(?:\d+(?:\.\d+)?)?$|^pypy3?$|^py$/u.test(name)) return PYTHON;
   return Object.hasOwn(INTERPRETERS, name) ? INTERPRETERS[name] : undefined;
 }
 
 
@@ -583,6 +583,16 @@ describe("commandHighlightLanguage", () => {
     ["git status; pwsh -c 'Get-Date'", "shellscript"],
     ["cat <<'EOF' > notes.txt\npwsh\nEOF", "shellscript"],
     ["", "shellscript"],
+    // Windows agents also run PowerShell directly, without a pwsh wrapper.
+    ["Get-Content package.json | Select-String version", "powershell"],
+    ["$env:CI='1'; npm test", "powershell"],
+    ["$tmp = Join-Path $env:TEMP repo; git clone example", "powershell"],
+    ['"=== CHECK FILE ==="; Get-Content file.txt', "powershell"],
+    ["& 'C:\\Python312\\python.exe' -c 'print(1)'", "powershell"],
+    ["update-alternatives --list java", "shellscript"],
+    ["echo Get-Content; git status", "shellscript"],
+    ["FOO=1 npm test", "shellscript"],
+    ["echo $HOME && ls", "shellscript"],
   ])("%s", (command, language) => {
     expect(commandHighlightLanguage(command)).toBe(language);
   });
 
@@ -1410,13 +1410,43 @@ function withoutShellWrapper(command: string): string {
 
 const POWERSHELL_PROGRAMS = new Set(["powershell", "pwsh"]);
 
-/** The grammar to highlight a command with: PowerShell when pwsh or powershell runs it. */
+// Common approved PowerShell verbs. Cmdlets are capitalized Verb-Noun, which
+// keeps lowercase Linux tools such as `update-alternatives` out.
+const POWERSHELL_CMDLET =
+  /^(?:Add|Clear|Compare|Compress|ConvertFrom|ConvertTo|Copy|Expand|Export|ForEach|Format|Get|Group|Import|Invoke|Join|Measure|Move|New|Out|Pop|Push|Read|Remove|Rename|Resolve|Select|Set|Sort|Split|Start|Stop|Test|Wait|Where|Write)-[A-Z][A-Za-z]*$/u;
+
+/**
+ * The grammar to highlight a command with: PowerShell when pwsh or powershell
+ * runs it, or when it is written in PowerShell, as Windows agents run it.
+ */
 export function commandHighlightLanguage(command: string): "powershell" | "shellscript" {
   const program = /^(?:&\s*)?(?:"([^"]*)"|'([^']*)'|(\S+))/u.exec(command.trim());
   const name = (program?.[1] ?? program?.[2] ?? program?.[3] ?? "")
     .split(/[\\/]/u)
     .at(-1)
     ?.toLowerCase()
     .replace(/\.exe$/u, "");
-  return name && POWERSHELL_PROGRAMS.has(name) ? "powershell" : "shellscript";
+  if (name && POWERSHELL_PROGRAMS.has(name)) return "powershell";
+  return isPowerShellScript(command) ? "powershell" : "shellscript";
+}
+
+/** Whether any statement starts like PowerShell and never like POSIX shell. */
+function isPowerShellScript(command: string): boolean {
+  let rest: string | null = command.trim();
+  // A leading call operator; POSIX shell cannot start a command with `&`.
+  if (/^&\s*\S/u.test(rest)) return true;
+  for (let segment = 0; rest && segment < MAX_COMMAND_SEGMENTS; segment += 1) {
+    const { firstCommand, remainingCommand } = splitFirstShellCommand(rest);
+    const statement = firstCommand.trim();
+    if (
+      // `$env:NAME` or `$name = value`; neither parses as POSIX shell.
+      /^\$(?:env|global|local|script):/iu.test(statement) ||
+      /^\$[A-Za-z_]\w*\s+=/u.test(statement) ||
+      POWERSHELL_CMDLET.test(statement.match(/^\S+/u)?.[0] ?? "")
+    ) {
+      return true;
+    }
+    rest = remainingCommand;
+  }
+  return false;
 }
Original file line number	Diff line number	Diff line change
`@@ -262,11 +262,14 @@ function forEachCommand(`
`262`	`262`	`}`
`263`	`263`
`264`	`264`	`function programName(word: Word): string {`
`265`		`- return (word.value.split(/[\\/]/u).at(-1) ?? "").toLowerCase().replace(/\.exe$/u, "");`
	`265`	+ // Bash reads `C:\Python312\python.exe` unquoted as escapes; Windows meant a path.
	`266`	`+ const path = /\\/u.test(word.text) ? word.text.replace(/^["']\|["']$/gu, "") : word.value;`
	`267`	`+ return (path.split(/[\\/]/u).at(-1) ?? "").toLowerCase().replace(/\.exe$/u, "");`
`266`	`268`	`}`
`267`	`269`
`268`	`270`	`function interpreterFor(name: string): Interpreter \| undefined {`
`269`		`- if (/^python(?:\d+(?:\.\d+)?)?$\|^pypy3?$/u.test(name)) return PYTHON;`
	`271`	+ // `py` is the Windows Python launcher, as in `py -3 -c '…'`.
	`272`	`+ if (/^python(?:\d+(?:\.\d+)?)?$\|^pypy3?$\|^py$/u.test(name)) return PYTHON;`
`270`	`273`	`return Object.hasOwn(INTERPRETERS, name) ? INTERPRETERS[name] : undefined;`
`271`	`274`	`}`
`272`	`275`