Over time, after cycling through many different programs on your system and since deleting them, the system can become clogged with traces of the old software. Manually deleting some programs is fine, but other dig themselves into the OS and if you delete them, there are still traces. All Windows programs create entries in the Windows registry and these entries are often still there after the program is long gone. This can lead to a long registry file and it bogs performance. Many good programs exist that uninstall old software and are quite good at removing every trace.
Many programs come equipped with their own uninstalling program.
Still other programs are designed to clean out Windows registry. Inc. All Rights Reserved.