Most of the softwares that you install put some files in the Windows directory, and almost definitely add new entries to the registry. Although most softwares come with their own uninstaller utility, test shows that they only very rarely remove all the entries that they have added.
My Uninstaller is a software which will attempt to monitor registry entries in such way that you can later view or remove them by your command. Note that Uninstaller needs to be running during the installation procedure of the software which you want to monitor.
To put it simply, Uninstaller compares the state of your system before and after the installation of some package to keep a record of things that were added (not changed) to your system.
Later on you can select the record and choose to view/delete it or go for an automatic uninstallation following the record. The automatic uninstallation will erase everything that you havn't deselected from the record. (For example, if the record shows 'MSVCRT.DLL' with other files, and you do not want to remove it, then you can unheck this file to keep it from being removed automatically.)