CCleaner (Crap Cleaner), ücretsiz PC optimizasyon aracıdır. Program ile kullanılmayan, gereksiz dosyalar bir fare tıklaması ile temizlenebiliyor. Program, Windows kayıt defterindeki (registry) gereksiz dosyaları da silebiliyor. Bunun yanı sıra programın “Tools” bölümünden, kaldırıldığı halde Program Ekle/Kaldır’da listenenen uygulamaları temizleyebilirsiniz.

Temizlediği Bileşenler:
- Internet Explorer
- Geçici dosyalar
- URL geçmişi
- Önbellek (cache)
- Çerezler (cookie)
- Index.dat dosyası
- Firefox
- Geçici dosyalar
- Önbellek (cache)
- Geri Dönüşüm Kutusu
- Pano (clipboard)
- Windows geçici dosyaları
- Windows günlük (log) dosyaları
- En son kullanılan belgeler listesi (Başlat Menüsü üzerindeki)
- Çalıştırılmış dosya geçmişi (Başlat Menüsü üzerindeki)
- Windows XP Arama Asistan geçmişi

Kapsadığı Uygulamalar:
Firefox, Opera, Media Player, Msn Messenger, eMule, Kazaa, Google Toolbar, Netscape, Office XP, Nero, Adobe Acrobat, Adobe Photoshop, WinRAR, WinAce, WinZip, CuteFTP, Quick Time, Nero ve daha fazlası..

CCleaner is a freeware system optimization and privacy tool. It removes unused files from your system - allowing Windows to run faster and freeing up valuable hard disk space. It also cleans traces of your online activities such as your Internet history. But the best part is that it's fast (normally taking less than a second to run) and contains NO Spyware or Adware!

Cleans the following:
• Internet Explorer: Temporary files, URL history, cookies, Autocomplete form history, index.dat.
• Firefox: Temporary files, URL history, cookies, download history.
• Google Chrome: Temporary files, history, cookies, download history, form history.
• Opera: Temporary files, URL history, cookies.
• Safari: Temporary files, history, cookies, form history.
• Windows: Recycle Bin, Recent Documents, Temporary files and Log files.
• Registry cleaner: Advanced features to remove unused and old entries, including File Extensions, ActiveX Controls, ClassIDs, ProgIDs, Uninstallers, Shared DLLs, Fonts, Help Files, Application Paths, Icons, Invalid Shortcuts and more... also comes with a comprehensive backup feature.
• Third-party applications: mRemoves temp files and recent file lists (MRUs) from many apps including Media Player, eMule, Kazaa, Google Toolbar, Netscape, MS Office, Nero, Adobe Acrobat, WinRAR, WinAce, WinZip and many more...
• 100% Spyware FREE: This software does NOT contain any Spyware, Adware or Viruses.

Features of CCleaner 2.0:
* Complete rebuild in C++
With the requirements for a portable version, 64-bit compatibility and Windows Vista increasing against the limitations of the old architecture. We decided to rebuild the entire CCleaner application in highly optimized C++.
* Faster analyzing and cleaning
Each scanning process was rewritten from scratch and fully optimized. The result being a noticeable speed increase in all areas.
* Portable
CCleaner can now run from a USB thumbdrive and be installed/run on a computer without a complicated setup process.
* Compact
The rewrite removed all external file dependencies, so the main EXE is now half the size of the original program and support files.
* Redesigned User Interface
The original CCleaner user interface was looking a little dated, so the GUI was redesigned with a modern look, but without sacrificing speed or usability. New icons were created for the interface and the main program icon was updated with a more modern style.
* Exclusions
It is now possible to specify files, folders and registry keys to ignore from the cleaning process.
* Loads of little tweaks
Too numerous to mention them all separately, we've tried to improve CCleaner in all areas.

Changes in CCleaner v2.21.940:
- Added U3 smart drive support. (Separate installer)
- Added support for: Adobe Reader 9.0, Adobe Photoshop CS3, Adobe Photoshop CS4, Adobe Illustrator CS4, Nero Burning ROM 9, OpenOffice 3.1, AVG AntiVirus 8.0, AntiVir Desktop and Vuze.
- Added Installed date and size to Uninstall Tool.
- Added support for multiple item selection on Start up tool.
- Added support for cleaning Windows 2008 IIS log files.
- Improved Windows 7 support.
- Improved 64-bit Registry cleaning accuracy.
- Improved loading of System Restore Tool.
- Improved various routines in the uninstaller code.
- Fixed Windows 7 Task Scheduler bug.
- Fixed "No Disk" bug when using Wipe Free Space.
- Fixed Win98 support.
- Minor text and translation improvements.
- Minor bug fixes.