Directly deleting a program's directory recovers space on your hard drive, but doesn't properly uninstall the program, and can lead to glitches when Windows or another program expects the deleted application to run. Instead, use the Programs and Features Control Panel in Windows 7 or 8 to uninstall the application, and then clean up residual files if necessary.
Open the Windows 7 Start menu, search for "Programs and Features" and select it from the Control Panel section of the search results. For Windows 8, press "Windows-X" and pick "Programs and Features" from the menu.
Open the drop-down menu by the "View" button to switch to "Details" view, which shows information about each installed program. To sort the list, click a column heading, such as "Size." Not all programs display every piece of information, however: A program might report no size, even though it takes up a lot of drive space.
Right-click any column heading and choose "More" to add additional columns of information. Items such as "Last Used On" help to find programs that you don't need anymore, but -- as with the Size column -- many programs won't correctly report the date of last use.
Select an unwanted program and press "Uninstall" or "Uninstall/Change" to run its uninstaller. Some programs have custom uninstallers that guide you through a multi-step process, but the standard uninstaller displays a simple "Yes" or "No" dialog box to confirm the removal.
Press "Change" or "Repair" when a selected program offers these options to make changes to an installation rather than remove it entirely. "Change" usually allows you to add or remove specific program components, while "Repair" helps with a malfunctioning program. With many applications, however, both buttons lead to the same window, which offers more specific options.
If you come across leftover folders from an uninstalled program, you can usually erase them safely. Look for these leftovers in the "Program Files" and "Program Files (x86)" directories on your hard drive, but wait until after your next reboot -- some uninstallers don't finish cleaning up until you reboot your PC. Another option: leave these folders behind and don't worry about them. Program leftovers rarely take up much space, and might contain program settings to retain your preferences if you reinstall the program later.
Programs that don't use an installer won't show up in the Programs and Features list. For example, many freeware programs downloaded from the Internet consist of an application that you can run without installation. You can safely delete these types of programs with the Recycle Bin.
Some programs, including annoying adware and toolbars installed alongside other utilities, maliciously hide themselves from the Programs and Features list. To get rid of these "Potentially Unwanted Programs," run scans in both your anti-virus program and a free malware scanner, such as Malwarebytes, Spybot or AdwCleaner (links in Resources). If an unwanted program remains after using one of these malware scanners, try another.
Uninstalling a program won't erase documents created with that program. For example, uninstalling Office won't delete your Word documents, but will prevent you from opening them until you install another word processor.
Uninstalled programs often leave behind entries in the Windows Registry, but you usually don't need to erase these entries. Leaving them in the Registry shouldn't cause any problems, whereas erasing a Registry entry incorrectly can break your system.