Unwinding windows uninstallation

Have you ever wondered how control panel is able to uninstall programs?

Upon any program installation, the installation details are maintained in below registry.

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{GUID}
GUID ->Unique product code set for the product by installer programs.

During uninstall, windows checks for "UninstallString" key value.

Most likely it would contain entry as like below.

MsiExec.exe /X{GUID}
MsiExec.exe -> Windows Installer Program that comes are part of OS installation.

It has many argument and X is to uninstall.

Below example is for ISS 10.0 Express.

Also windows takes a copy of the installer files to "C:\Windows\Installer" with some auto-generated name for which windows has a mapping with product code.

With this, it is able to uninstall a product!

More information:

Uninstall Registry Key

MsiExec Command-Line Options