diff --git a/deploy/windows/installer/shopdb-preflight.ps1 b/deploy/windows/installer/shopdb-preflight.ps1
index 5a8c24d..424afe3 100644
--- a/deploy/windows/installer/shopdb-preflight.ps1
+++ b/deploy/windows/installer/shopdb-preflight.ps1
@@ -221,8 +221,12 @@ Invoke-Check 'Network' 'Site port' {
             Add-Result 'Network' 'Site port' 'INFO' `
                 "TCP $SitePort is used by the existing $SiteName site - this will be upgraded in place"
         } else {
-            Add-Result 'Network' 'Site port' 'FAIL' "TCP $SitePort is in use$owner" `
-                "Choose a different port with -SitePort, or stop the listener."
+            # WARN, not FAIL. This check runs before the operator has reached the
+            # Address page, so it is testing the DEFAULT port, not necessarily
+            # the one they intend to use. Blocking here would refuse an install
+            # over a conflict the very next page lets them resolve.
+            Add-Result 'Network' 'Site port' 'WARN' "TCP $SitePort is in use$owner" `
+                "Pick a different port on the Address page later in this wizard, or stop whatever is holding it."
         }
     }
 }
@@ -266,8 +270,13 @@ Invoke-Check 'IIS' 'HttpPlatformHandler' {
     if ($modules -match 'httpPlatformHandler') {
         Add-Result 'IIS' 'HttpPlatformHandler' 'PASS' 'installed'
     } else {
-        Add-Result 'IIS' 'HttpPlatformHandler' 'FAIL' 'not installed' `
-            'Install httpPlatformHandler_amd64.msi from the bundle. IIS cannot launch waitress without it.'
+        # NOT a blocker: the MSI is in the bundle and stage 4 installs it. This
+        # was a FAIL, which - once the preflight page started blocking on any
+        # failure - stopped the wizard dead over something the installer was
+        # about to do by itself, with no way forward but to go and install it by
+        # hand. Nothing the installer SUPPLIES may be a blocker.
+        Add-Result 'IIS' 'HttpPlatformHandler' 'INFO' 'not installed yet' `
+            'The installer installs it from the bundle. No action needed.'
     }
 }
 
diff --git a/tests/test_installer_defaults.py b/tests/test_installer_defaults.py
index 1d479eb..a6b39f3 100644
--- a/tests/test_installer_defaults.py
+++ b/tests/test_installer_defaults.py
@@ -53,3 +53,32 @@ def test_every_wizard_exclusion_is_a_real_plugin():
     for name in wizard_excludes():
         assert (PLUGINS / name / 'manifest.json').exists(), (
             '%s is excluded by the wizard but has no manifest' % name)
+
+
+# The preflight blocks the wizard on any FAIL. That is correct for something the
+# operator must go and fix, and wrong for anything the installer carries in its
+# own bundle - there, blocking stops the wizard over something it was about to do
+# itself, with no way forward.
+BUNDLE_SUPPLIED = [
+    'HttpPlatformHandler',   # httpplatformhandler\*.msi, installed by stage 4
+    'URL Rewrite',           # urlrewrite\*.msi, installed by stage 4
+]
+
+PREFLIGHT = REPO / 'deploy' / 'windows' / 'installer' / 'shopdb-preflight.ps1'
+
+
+def test_nothing_the_bundle_supplies_is_a_blocker():
+    """Regression: HttpPlatformHandler was a FAIL, so a server without it could
+    not get past the preflight page - to install the very thing that was
+    missing."""
+    text = PREFLIGHT.read_text(encoding='utf-8', errors='replace')
+    offenders = []
+    for line in text.splitlines():
+        if "'FAIL'" not in line:
+            continue
+        for component in BUNDLE_SUPPLIED:
+            if component.lower() in line.lower():
+                offenders.append(line.strip())
+    assert not offenders, (
+        'the installer supplies these, so they must not block the wizard:\n  %s'
+        % '\n  '.join(offenders))