diff --git a/bin/gstack-doctor b/bin/gstack-doctor
index 75be5e044..c54525bff 100755
--- a/bin/gstack-doctor
+++ b/bin/gstack-doctor
@@ -88,8 +88,9 @@ row() {
   esac
 }
 
-# sq TEXT — TEXT single-quoted for bash.
+# sq TEXT — TEXT single-quoted for bash; psq TEXT — single-quoted for PowerShell.
 sq() { printf "'%s'" "$(printf '%s' "$1" | sed "s/'/'\\\\''/g")"; }
+psq() { printf "'%s'" "$(printf '%s' "$1" | sed "s/'/''/g")"; }
 
 # clamp CHARSET MAX — stdin's first line reduced to CHARSET, at most MAX chars.
 clamp() { head -1 | tr -cd "$1" | cut -c1-"$2"; }
diff --git a/bin/gstack-doctor-check.sh b/bin/gstack-doctor-check.sh
index 8c5a49cf7..016acf266 100644
--- a/bin/gstack-doctor-check.sh
+++ b/bin/gstack-doctor-check.sh
@@ -2,8 +2,8 @@
 # gstack-doctor-check.sh — `gstack-doctor --check`: the one-line install verdict.
 #
 # Sourced by bin/gstack-doctor after its prelude (ROOT, ROOT_REAL, BIN, SRC,
-# DOCS, STATE_ROOT, EXE, clamp, the launch probe, the codex status helpers)
-# and never executed on its own. Prints `required: <ids>`, one
+# DOCS, STATE_ROOT, EXE, WINDOWS, clamp, sq, psq, the launch probe, the codex
+# status helpers) and never executed on its own. Prints `required: <ids>`, one
 # `PASS | FAIL | SKIP <id>` row per component in bin/gstack-doctor-components.sh
 # (generated from lib/doctor-components.ts; the same ids feed --for, --require
 # and --json), then exactly one trailer: `gstack: ok <revision> for=<what>` on
@@ -16,7 +16,8 @@
 # Inputs (set by bin/gstack-doctor): CHECK_FOR (skill), CHECK_REQUIRE (csv),
 # CHECK_JSON (0|1), CHECK_PROJECT (path or ""), CHECK_REVISION (ref or ""),
 # CHECK_MIN_REVISION (the supported minimum the Capy wrapper read from the
-# remote's capy/support.env, `unknown` when its fetch failed, or ""), LIVE.
+# remote's capy/support.env, `unknown` when its fetch failed, or ""), LIVE,
+# WINDOWS (1 on Windows; GSTACK_DOCTOR_PLATFORM overrides the detection).
 # GSTACK_CAPY_WRAPPER_PATH (optional) names the wrapper a below-minimum fix runs.
 
 . "$BIN/gstack-doctor-components.sh" || { echo "gstack-doctor: $BIN/gstack-doctor-components.sh is missing; reinstall with cd $SRC && ./setup" >&2; exit 1; }
@@ -378,6 +379,21 @@ _dc_version_below() {
   return 1
 }
 
+# _dc_upgrade_cmd — the command that moves this install to the latest release.
+# On Windows bin/gstack-upgrade refuses every Git Bash install (it compares a
+# pwd -P /c/... path with git's C:/... toplevel), so the held-install recovery
+# forms from docs/troubleshooting.md#auto-update-held-install-recovery are
+# named instead, one per shell, with the install path quoted for each.
+_dc_upgrade_cmd() {
+  local win
+  if [ "$WINDOWS" -ne 1 ]; then printf '%s' "$SRC/bin/gstack-upgrade"; return; fi
+  win=$(cygpath -w "$SRC" 2>/dev/null) || win="$SRC"
+  printf '%s' "run the held-install recovery (bin/gstack-upgrade refuses on Git Bash installs): in Git Bash: cd $(sq "$SRC")"
+  printf '%s' ' && git fetch origin main && d=$(mktemp -d) && git show FETCH_HEAD:bin/gstack-ff-update > "$d/gstack-ff-update" && bash "$d/gstack-ff-update" . FETCH_HEAD; s=$?; rm -rf "$d"; [ "$s" = 0 ] && ./setup'
+  printf '%s' " — or in Windows PowerShell 5.1: Set-Location -LiteralPath $(psq "$win")"
+  printf '%s' " -ErrorAction Stop; \$gb = Join-Path (git --exec-path) '..\\..\\..\\bin\\bash.exe'; & \$gb -c 'set -f; IFS=; git fetch origin main && d=\$(mktemp -d) && git show FETCH_HEAD:bin/gstack-ff-update > \$d/gstack-ff-update && bash \$d/gstack-ff-update . FETCH_HEAD; s=\$?; rm -rf -- \$d; exit \$s'; if (\$LASTEXITCODE -eq 0) { .\\setup.ps1 }"
+}
+
 # _dc_check_min_revision INSTALLED HEAD — sets the PASS-row suffix _dc_min_note,
 # or prints the REVISION_BELOW_MINIMUM FAIL row for --min-revision and returns 1.
 # Returns 1 after printing a FAIL row.
@@ -390,7 +406,9 @@ _dc_check_min_revision() {
   esac
   if _dc_version_below "$installed" "$CHECK_MIN_REVISION"; then
     if [ -n "${GSTACK_CAPY_WRAPPER_PATH:-}" ]; then
-      fix="bash $GSTACK_CAPY_WRAPPER_PATH${CHECK_FOR:+ --for $CHECK_FOR} (fast-forwards), or $SRC/bin/gstack-upgrade"
+      fix="bash $GSTACK_CAPY_WRAPPER_PATH${CHECK_FOR:+ --for $CHECK_FOR} (fast-forwards), or $(_dc_upgrade_cmd)"
+    elif [ "$WINDOWS" -eq 1 ]; then
+      fix="$(_dc_upgrade_cmd)"
     else
       fix="$SRC/bin/gstack-upgrade (fast-forwards to the remote default branch, then reinstalls)"
     fi
@@ -419,7 +437,9 @@ _dc_check_revision() {
     _dc_row PASS revision "$installed ($head) is --revision $want$_dc_min_note"
     return
   fi
-  _dc_row FAIL revision "installed ${installed:-unknown}${head:+ at $head} (requested $want)" "cd $SRC && git fetch origin && git checkout $want && ./setup, or run $SRC/bin/gstack-upgrade to move to the latest release (interactive: /gstack-upgrade)" REVISION_UNMET
+  local latest="run $SRC/bin/gstack-upgrade to move to the latest release (interactive: /gstack-upgrade)"
+  [ "$WINDOWS" -eq 1 ] && latest="to move to the latest release, $(_dc_upgrade_cmd)"
+  _dc_row FAIL revision "installed ${installed:-unknown}${head:+ at $head} (requested $want)" "cd $SRC && git fetch origin && git checkout $want && ./setup, or $latest" REVISION_UNMET
 }
 
 # _dc_wrapper_rev FILE — the GSTACK_CAPY_WRAPPER revision a Capy skill copy
diff --git a/test/gstack-doctor.test.ts b/test/gstack-doctor.test.ts
index ccc57c759..aa2c7c53a 100644
--- a/test/gstack-doctor.test.ts
+++ b/test/gstack-doctor.test.ts
@@ -760,7 +760,8 @@ describe('gstack-doctor --check: launch Bun, supported minimum, planning-only pi
     expect(below.rows.revision.status).toBe('FAIL');
     expect(below.rows.revision.rest).toContain(`installed ${VERSION}`);
     expect(below.rows.revision.rest).toContain('below the supported minimum 99.0.0.0');
-    expect(below.rows.revision.rest).toContain(`${bashPath(f.root)}/bin/gstack-upgrade`);
+    // On Windows the fix names the held-install recovery instead (bin/gstack-upgrade refuses Git Bash installs).
+    expect(below.rows.revision.rest).toContain(process.platform === 'win32' ? 'in Git Bash: ' : `${bashPath(f.root)}/bin/gstack-upgrade`);
     expect(below.rows.revision.rest).toContain('(REVISION_BELOW_MINIMUM; ');
     expect(below.trailer).toBe('gstack: fail revision');
     const wrapped = check(f, ['--min-revision', '99.0.0.0'], { GSTACK_CAPY_WRAPPER_PATH: '/drive/skills/gstack/scripts/install.sh' });
@@ -1033,4 +1034,43 @@ describe('gstack-doctor: rescue refs, CLAUDE.md skill lists, Windows bash, Windo
     expect(refused.status).toBe(1);
     expect(doctor(f, [], { GSTACK_DOCTOR_PLATFORM: 'posix' }).out).not.toContain('windows bash');
   });
+
+  /** A held-install recovery form from docs/troubleshooting.md (the line after its form marker's fence). */
+  const form = (name: string) => {
+    const doc = fs.readFileSync(path.join(REPO, 'docs/troubleshooting.md'), 'utf8');
+    return doc.slice(doc.indexOf(`<!-- form:${name} -->`)).match(/```[a-z]+\n([^\n]+)\n```/)![1];
+  };
+  const check = (f: Fixture, args: string[], extra: Record<string, string> = {}) => {
+    const r = doctor(f, ['--check', ...args], extra);
+    return { ...r, revision: r.out.split('\n').find(l => /^(PASS|FAIL) revision\b/.test(l)) ?? '' };
+  };
+
+  test('--check on Windows: the upgrade fix names both held-install recovery forms, each labelled by shell with the install path quoted, never bin/gstack-upgrade; elsewhere it keeps bin/gstack-upgrade', () => {
+    const f = makeFixture();
+    const root = bashPath(f.root);
+    const win = spawnSync('bash', ['-c', 'cygpath -w "$1" 2>/dev/null || printf %s "$1"', '_', root], { encoding: 'utf8', timeout: 10_000 }).stdout.trim();
+    const gitBash = form('recovery-gitbash').replace('cd ~/.claude/skills/gstack', `cd '${root}'`);
+    const powershell = form('recovery-powershell').replace('"$HOME\\.claude\\skills\\gstack"', `'${win}'`);
+    expect(gitBash).toContain(`cd '${root}' && `);
+    expect(powershell).toContain(`Set-Location -LiteralPath '${win}' `);
+    const windows = { GSTACK_DOCTOR_PLATFORM: 'windows' };
+    for (const [args, extra] of [
+      [['--min-revision', '99.0.0.0'], windows],
+      [['--min-revision', '99.0.0.0'], { ...windows, GSTACK_CAPY_WRAPPER_PATH: '/drive/skills/gstack/scripts/install.sh' }],
+      [['--revision', 'v0.0.0.1'], windows],
+    ] as Array<[string[], Record<string, string>]>) {
+      const r = check(f, args, extra);
+      expect(r.revision, r.out).toStartWith('FAIL revision');
+      expect(r.revision).toContain(`in Git Bash: ${gitBash}`);
+      expect(r.revision).toContain(`in Windows PowerShell 5.1: ${powershell}`);
+      expect(r.revision).not.toContain(`${root}/bin/gstack-upgrade`);
+    }
+    expect(spawnSync('bash', ['-n', '-c', gitBash], { encoding: 'utf8', timeout: 10_000 }).status).toBe(0);
+    const json = JSON.parse(doctor(f, ['--check', '--json', '--min-revision', '99.0.0.0'], windows).out);
+    expect(json.rows.find((x: { id: string }) => x.id === 'revision').fix).toContain(`in Windows PowerShell 5.1: ${powershell}`);
+    const posix = check(f, ['--min-revision', '99.0.0.0'], { GSTACK_DOCTOR_PLATFORM: 'posix' });
+    expect(posix.revision).toContain(`fix: ${root}/bin/gstack-upgrade (fast-forwards to the remote default branch, then reinstalls)`);
+    expect(posix.revision).not.toContain('in Git Bash:');
+    expect(check(f, ['--revision', 'v0.0.0.1'], { GSTACK_DOCTOR_PLATFORM: 'posix' }).revision).toContain(`or run ${root}/bin/gstack-upgrade to move to the latest release`);
+  });
 });