diff --git a/.github/scripts/build_packages.py b/.github/scripts/build_packages.py
index 5e32861..e503b14 100644
--- a/.github/scripts/build_packages.py
+++ b/.github/scripts/build_packages.py
@@ -83,17 +83,37 @@
 
 
 def how_to_start(package, feed):
-    """The paragraph that differs by feed: what the package gives and how to start it."""
+    """The paragraph that differs by feed: what the package gives and how to start it.
+
+    The WinGet sentences about upgrading are measured, not assumed, with WinGet
+    1.29.380 on 2026-09-25: on Windows Server 2025 in machine scope and on
+    Windows 11 in user scope, upgrading the window while it was open failed
+    with "Access is denied" and left the package folder half removed until the
+    upgrade ran again with the window closed. On Windows 11 the command line
+    did the same while a tfg command was running. A portable package can carry
+    no script to warn at that moment, so the description is the only place a
+    person can read it first.
+    """
     other = next(p for p in PACKAGES if p is not package)
     other_id = other.winget_id if feed == "winget" else other.choco_id
     if package.kind == "cli":
-        return ("This package is the command line, for scripts and pipelines. The desktop "
+        text = ("This package is the command line, for scripts and pipelines. The desktop "
                 "window is the package %s. Type tfg help to see the commands." % other_id)
+        if feed == "winget":
+            # "when tfg is not running" rather than naming a command: any tfg
+            # command holds the program file while it runs, and "a tfg run" read
+            # as a command that does not exist (outside review of #144).
+            text += (" Upgrade it when tfg is not running. WinGet cannot replace tfg while "
+                     "it runs, so it stops half way, and the package works again once the "
+                     "upgrade runs after tfg has finished.")
+        return text
     if feed == "winget":
         return ("This package is the desktop window. The command line is the package %s. "
                 "WinGet adds no Start menu shortcut for it. Open a new terminal and type "
                 "tfg-gui. The window offers a tfg-out folder in the directory it was started "
-                "from." % other_id)
+                "from. Close the window before you upgrade. WinGet cannot replace a running "
+                "program, so it stops half way, and the package works again once the "
+                "upgrade runs with the window closed." % other_id)
     return ("This package is the desktop window. The command line is the package %s. It "
             "adds a Start menu shortcut and the tfg-gui command. Started from the shortcut, "
             "the window offers a tfg-out folder in your user profile." % other_id)
diff --git a/packaging/README.md b/packaging/README.md
index cc7acb4..d6cb146 100644
--- a/packaging/README.md
+++ b/packaging/README.md
@@ -35,7 +35,13 @@ the real file. With it, WinGet makes no link and puts the package's folder on
 `PATH`. The command line would work either way, but without the field its shape
 depends on the machine - a link where symbolic links are allowed, the folder on
 `PATH` where they are not. WinGet adds no Start menu shortcut for a portable
-package, and the window's description says so.
+package, and the window's description says so. One cost of the field is not
+ours to fix. WinGet 1.29.380 left the package's folder on `PATH` after an
+uninstall, for both of these packages, in machine scope on Windows Server 2025
+and in user scope on Windows 11 - measured on 2026-09-25, the entry stays and
+points at a folder that no longer exists.
+[microsoft/winget-cli#6160](https://github.com/microsoft/winget-cli/issues/6160),
+open, reports the same for another package that sets the field.
 
 **Chocolatey.** The package downloads the release archive rather than carrying
 it, so it holds no binaries and owes no `VERIFICATION.txt`, and the archive is the
@@ -50,10 +56,23 @@ into the package. The icon is a jsDelivr address pinned to the release tag:
 moderation refuses `raw.githubusercontent.com` and `github.com/.../raw` alike,
 and an icon on a branch would keep changing under an approved package.
 
-**Neither package ends a running program.** `chocolateybeforemodify.ps1` says when
-the program is still running from the package, and leaves closing it to the
-person - a run in progress may be halfway through a set of files, and cutting it
-would leave files with no manifest to say what they are.
+**Neither package ends a running program** - a run in progress may be halfway
+through a set of files, and cutting it would leave files with no manifest to say
+what they are. What each feed does instead was measured on 2026-09-25, with the
+program running - Chocolatey on Windows Server 2025, WinGet there in machine
+scope and on Windows 11 in user scope:
+
+- **Chocolatey goes ahead**, an upgrade and an uninstall alike, and reports
+  success. It moves the package folder aside to `lib-bkp`, and the running copy
+  keeps working from there - but it cannot delete that copy, so the copy stays:
+  after an upgrade until the next Chocolatey operation on the package, after an
+  uninstall for good. `chocolateybeforemodify.ps1` says so at that moment and
+  names the folder to delete once the program is closed.
+- **WinGet stops half way.** An upgrade fails with "Access is denied" on the
+  program, having already deleted some of the other files, and the package works
+  again once the upgrade runs with the program closed. Measured for the window
+  and, on Windows 11, for the command line while a tfg command was running. A portable
+  package carries no script, so the description is where this is said.
 
 ## Submitting
 
diff --git a/packaging/chocolatey/tools/chocolateybeforemodify.ps1.in b/packaging/chocolatey/tools/chocolateybeforemodify.ps1.in
index 88b79ba..3d2a8c5 100644
--- a/packaging/chocolatey/tools/chocolateybeforemodify.ps1.in
+++ b/packaging/chocolatey/tools/chocolateybeforemodify.ps1.in
@@ -2,8 +2,15 @@
 #
 # Chocolatey runs this from the INSTALLED package before an upgrade or an
 # uninstall. It says so when the program is still running from this package,
-# because Windows does not let the files of a running program be replaced, and
-# a person should hear why before the operation that follows complains.
+# and it says what will really happen, which was measured rather than assumed
+# (Windows Server 2025, docs/PACKAGING-2026-09-25.md section 10). It does not
+# fail: Chocolatey moves the package folder aside to lib-bkp, goes ahead and
+# reports success, and the running copy keeps working from there. What it
+# cannot do is delete that copy while it runs, so the copy stays in lib-bkp -
+# after an upgrade until the next Chocolatey operation on this package, and
+# after an uninstall for good, because there may be no next operation. The
+# first version of this message said the operation would fail, which it did
+# not.
 #
 # It never ends the program. That is the owner's decision of 2026-09-25: a run
 # in progress may be halfway through writing a set of files, and cutting it
@@ -28,5 +35,7 @@ try {
 }
 
 if ($running.Count -gt 0) {
-    Write-Warning '{{TITLE}} is running from this package. Close it before you upgrade or remove the package. Windows does not let the files of a running program be replaced.'
+    $leftover = Join-Path $env:ChocolateyInstall 'lib-bkp\{{CHOCO_ID}}'
+    Write-Warning '{{TITLE}} is running from this package. Chocolatey goes ahead, but it cannot delete the running copy, so that copy stays behind.'
+    Write-Warning "It is left in $leftover. Close the program, then delete that folder."
 }