AutoCAD Installation Issue: Product Already Installed

Have you ever run into a situation where you go to install AutoCAD, and it acts as if it is already installed, but it is not actually installed?

If this is the second time you're installing on the PC, in most cases, the installer rolls back and sets everything back to the way it should be when you start the installer. However, in some cases, this does not happen. When you try to install AutoCAD, it acts as though the product is already installed.

Solution: Resetting the Installer

To reset the installer, we need to remove some registry entries. Before proceeding, it is important to backup the registry.

If the problem occurred when the last installation was aborted before completion, search for the following registry paths:

HKEY_CLASSES_ROOT\Installer\Products
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Installer\UserData\S-1-5-18\Products
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall

Under each of these paths, look for the Product Name and remove any keys from the GUID level. You can also search the entire registry for values pointing to non-existing installations and remove them.

Dealing with .MST Files

If the installation log shows that the installation initialization is detecting the existence of an .mst file and cannot proceed because of it, search the registry for the string of the .mst file name and delete that key from the GUID level.

Custom Action Failure: CheckForACADExistance

If the log file indicates that the failure is due to a custom action, CheckForACADExistance, navigate to the installation directory (usually C:\Program Files\AutoDesk\AutoCAD) and remove the AutoCAD directory.