track change to registry before installing software [duplicate]

Possible Duplicate:
What’s the easiest and fastest way to compare 2 registry files?

is there an application that can track any changes made to my registry before I install software on my windows 7 computer?

Revo Uninstaller does that:

Real-Time Installation Monitor - Revo Uninstaller Pro has real-time program installation monitoring. It detects system changes during installation, so you can undone them later.

and ...

Multi-Level Backup System - Revo Uninstaller Pro creates backups of removed registry keys, values, files and folders. It also creates full registry backup each time you uninstall a program.

If you looking for a freeware for tracking a particular program: WhatChanged or InstallSpy tracks registry & files changes

If it's for all your installs, like Molly, I recommend Revo Uninstaller