An orphan file is a file on a computer that has been rendered obsolete because the application or file it is linked with has been moved or deleted. The most common reason for an orphan file to be present on an operating system is an incomplete program uninstallation, as when someone simply deletes a program instead of running the uninstall utility. This leaves program files behind on the hard drive, although they have no purpose because the program is no longer in use. Orphan files can usually be deleted to free up space and create a clean hard drive in the event that someone needs to reinstall a program or file.
There are cases when a program file is used by several applications or by the system. In these instances, deleting the orphan file can cause errors. Other programs may fail to work or will malfunction until the file is restored to the system. Since it can sometimes be hard to tell if a file is truly an orphan or not, some people leave these files in place, as they are often small and do not take up very much hard drive space.
People can reduce the risk of creating orphan files on their computers by using the uninstall utilities packaged with programs when they need to remove a program. Usually the utility can be found in the menu folder for a given program, and opening the utility will provide people with a series of prompts. Once the program has been removed, the utility will seek out any files associated with the program, check to make sure they aren't being used by the system or other programs, and remove them.
Hard drive cleanup utilities are also available for orphan file management. These utilities will scan the hard drive for temporary files as well as files that do not appear to be associated with anything. The utility can be set to delete these files automatically, or to prompt the user to make sure the file can be removed. These utilities can help a computer run faster if it is getting close to the maximum file space on the hard drive and there are numerous unnecessary files.
The orphan file problem can come up in systems of all types and sizes. It is not always the fault of a user; sometimes programs don't uninstall correctly, or create temporary files with no use beyond installing or uninstalling and then fail to delete these files when they're done.