Disk Cleanup

Disk Clean-up (cleanmgr.exe) is a computer maintenance utility included in Microsoft Windows designed to free up disk space on a computer's hard drive. The utility first searches and analyzes the hard drive for files that are no longer of any use, and then removes the unnecessary files. There are a number of different file categories that Disk Clean-up targets when performing the initial disk analysis: The above list, however, is not exhaustive. For instance, 'Temporary Remote Desktop files' and 'Temporary Sync Files' may appear only under certain computer configurations, differences such as Windows Operating System and use of additional programs such as Remote Desktop. The option of removing hibernation data may not be ideal for some users as this may remove the hibernate option.
 * Compression of old files
 * Temporary Internet files
 * Temporary Windows files
 * Downloaded program files
 * Recycle Bin
 * Removal of unused applications or optional Windows components
 * Setup log files
 * Offline web pages (cached)
 * WinSxS (Windows component store)

Aside from removing unnecessary files, users also have the option of compressing files that have not been accessed over a set period of time. This option provides a systematic compression scheme. Infrequently accessed files are compressed to free up disk space while leaving the frequently used files uncompressed for faster read/write access times. If after file compression, a user wishes to access a compressed file, the access times may be increased and vary from system to system. In addition to the categories that appear on the Disk Clean-up tab, the More Options tab offers additional options for freeing up hard drive space through removal of optional Windows components, installed programs, and all but the most recent System Restore point or Shadow Copy data in some versions of Microsoft Windows.

Starting with Windows 10 version 1803 (RS4), the capabilities of Disk Clean-up are incorporated into Windows 10's Settings app.[1] The standalone Disk Clean-up tool itself is still included.

Microsoft announced that Disk Clean-up utility is Deprecated:

''The Disk Cleanup experience (“cleanmgr.exe”) is being deprecated. We’re retaining the Disk Cleanup tool for compatibility reasons. There’s no need to worry since Storage Sense’s functionality is a superset of what the legacy Disk Cleanup provides!''

Since Windows 10 version 1809 (RS5), the utility was renamed to "Disk Clean-up". It was previously named "Disk Cleanup".

Disk Space Analyzers also help in the clean up process. These allow comparison of relative disk space occupied by various items like Folders and Files. This helps decide which items to clean up first.