I have create a patch which is also uninstallable patch after applying the patch I can find my original files(dlls) are cached to baseline cache i.e windows\installer\$PatchCache$. But upon uninstall of my patch not all patched dlls are reverted back to the original version. So I wonder what could be reasons that some dlls are not reverted back upon uninstall of my patch. Note: dlls are in question not marked as shared components. In components table attribute field for those component I find value as 0 which is as designed.