If you are the person would like to give yourself a try for any freeware or trial software, then installing and uninstalling is a common process you usually perform on your computer. However, you probably unaware that many software actually don’t remove registry key cleanly from your computer even though you have uninstalled them properly. Too many left over junk keys may slow down your computer performance. If you would like to clean up left over junk keys, it is impossible to know and identify them without any help from tool. Now, there is a utility named as WhatChanged that is able to point out what are registry keys or files which have been added after installing software.

WhatChanged is freeware and is simple to use. It is able to scan and compare what are new registry keys or files that have been added. To use this tool, there are only two simple steps that you need to perform. First, you need to select items which you want to trace, either files or registry or both, then click Step #1: Get Baseline State button to get snapshot of registry or files before changes as a baseline. To know what items have been captured, you can get it from the output file generated at the same folder as WhatChanged tool. Secondly, once you have done the installation, click Step #2: Find what changed since Step #1 button. It will then compare and find out differences between the snapshot of before change and after change. The finding is generated in the text file which you can get it at the same folder as the WhatChanged tool. From the finding, you will know what are the new registry keys or files being added during the installation. If you find they still exist after you have uninstalled the software, then you can go and delete them manually since you already know and confirm they are no longer needed anymore.
WhatChanged 1.06 is compatible to run on Windows XP and Vista and only consume 92 KB of your hard disk space. It doesn’t require you to install and just run the executable file to launch it for immediate use. If you feel it is useful, just download it at here.