I’ve discussed a couple different reasons that Windows Installer 3.0-style patches – those with the MsiPatchMetadata table in the patch package itself – might not be uninstallable. I explained another reason in a discussion about the new patch build support in Windows Installer XML (WiX) v3 recently,
Patching with Windows Installer is the act of applying a pair of transforms in a patch to a Windows Installer product, then repairing that product. Any changes made in the transforms affect the aggregate view that Windows Installer reinstalls. This is displayed in the diagram below,
I have posted a Windows Live Writer plugin I wrote to aide posting URLs to MSDN, simply named Paste MSDN URL. It removes, if present, the culture in the URL so that when a reader clicks the link he or she sees the content on MSDN in their preferred language if a translation is available.