Registry monitoring settings

The Windows registry is a database which stores important configuration information for all the programs installed on your computer, for Windows and also for your computer's hardware. When a setup program installs an application, it usually adds a lot of entries to the registry.

In this settings tab you can specify registry monitoring options.

You can choose which keys you want to monitor. The default and also the recommended setting is to monitor all keys.

What the different registry keys are for

Each root key in the registry is used for keeping a different kind of information.

HKEY_LOCAL_MACHINE contains the software and hardware configuration of your computer.

HKEY_CURRENT_USER contains the software configuration for the user that is currently logged in.

HKEY_USERS contains the software configuration for all users

HKEY_CLASSES_ROOT contains some special (OLE, COM, Windows Explorer, etc) software configuration for all users.

HKEY_CURRENT_CONFIG contains hardware configration information

Monitoring type options

Live monitoring monitors the registry changes in real time. Immediately after the the setup program creates, deletes or modifies registry keys or values, the installation monitor finds out about it and writes this information to the installation log.

This is the recommended mode. However, this mode doesn't work on Windows 98, and you will have to use snapshot monitoring.

Snapshot monitoring works like this:

The installation monitor reads all the information from the registry and saves it as a registry snapshot.
The setup program of the application installs the application. During the installation, the setup program creates registry keys and values.
After the application has installed itself, the installation monitor makes another snapshot of the registry. That means it reads all the registry again and writes all this information to a snapshot.
The installation monitor compares the snapshot made before the installation with the snapshot made after the installation, and makes a list of registry keys and values that have been added, deleted or renamed by the installation program.

Because of the time required to create and compare the snapshots this mode takes a lot of time before and after installing the application.