Computer cleanup
- Disk Cleanup - Windows has a built-in disk cleanup tool
- CCleaner - Previously known as "crap cleaner" this is very popular
- BleachBit - Free, open-source disk cleanup application
- System Ninja - Cleans up some of the lesser known junk, but check for false positives when cleaning
- ExifCleaner - metadata removal application
Duplicate file cleanup
- dupeGuru - Free, open-source duplicate file remover
- Duplicate File Finder - an old but still useful tool to remove duplicates, although it isn't always accurate
- Czkawka - Free, open-source duplicate file remover, very versatile and my (Turtles) favorite pick at the moment