diff --git a/Misc/NEWS.d/next/Windows/2024-04-24-22-50-33.gh-issue-117505.gcTb_p.rst b/Misc/NEWS.d/next/Windows/2024-04-24-22-50-33.gh-issue-117505.gcTb_p.rst
new file mode 100644
index 00000000000..0931687ecc5
--- /dev/null
+++ b/Misc/NEWS.d/next/Windows/2024-04-24-22-50-33.gh-issue-117505.gcTb_p.rst
@@ -0,0 +1 @@
+Fixes an issue with the Windows installer not running ensurepip in a fully isolated environment. This could cause unexpected interactions with the user site-packages.
diff --git a/Tools/msi/pip/pip.wxs b/Tools/msi/pip/pip.wxs
index 1d8083cad91..627c4710a9f 100644
--- a/Tools/msi/pip/pip.wxs
+++ b/Tools/msi/pip/pip.wxs
@@ -25,8 +25,8 @@
         <?endif ?>
         
         <!-- Install/uninstall pip -->
-        <CustomAction Id="SetUpdatePipCommandLine" Property="UpdatePip" Value='"[PYTHON_EXE]" -E -s -m ensurepip -U --default-pip' Execute="immediate" />
-        <CustomAction Id="SetRemovePipCommandLine" Property="UpdatePip" Value='"[PYTHON_EXE]" -E -s -B -m ensurepip._uninstall' Execute="immediate" />
+        <CustomAction Id="SetUpdatePipCommandLine" Property="UpdatePip" Value='"[PYTHON_EXE]" -I -m ensurepip -U --default-pip' Execute="immediate" />
+        <CustomAction Id="SetRemovePipCommandLine" Property="UpdatePip" Value='"[PYTHON_EXE]" -I -B -m ensurepip._uninstall' Execute="immediate" />
         
         <InstallExecuteSequence>
             <Custom Action="SetUpdatePipCommandLine" Before="UpdatePip">(&amp;DefaultFeature=3) AND NOT (!DefaultFeature=3)</Custom>