CCleaner (Crap Cleaner) is a freeware system optimization tool. CCleaner removes unused and temporary files from your system - allowing it to run faster, more efficiently and giving you more hard disk space. CCleaner also comes with a registry scanner that scans for invalid references (advanced users) .

CCleaner是一款免費的系統優化和隱私保護工具。主要用來清除Windows系統不再使用的垃圾文件，以騰出更多硬盤空間。它的另一大功能是清除使用者的上網記錄。CCleaner的體積小，運行速度極快，可以對臨時文件夾、歷史記錄、回收站等進行垃圾清理，并可對注冊表進行垃圾項掃描、清理。附帶軟件卸載功能。同時支持IE、Firefox、Oprea等。免費使用，不含任何間諜軟件和垃圾程序。支持包括簡體中文在內的31國語言界面！

Cleans the following:

- Internet Explorer Cache, History, Cookies, Index.dat.
- Recycle Bin, Temporary files and Log files.
- Recently opened URLs and files.
- Third-party application temp files and recent file lists (MRUs).
- Including: Firefox, Opera, Media Player, eMule, Google Toolbar, Netscape, Office XP, Nero, Adobe Acrobat, WinRAR, WinAce, WinZip and more...
- Advanced Registry scanner and cleaner 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... Backup for registry clean.
- Windows Startup tool.

Changelog:

- Fixed problem with Vista UAC compatibility.
- Fixed bug in Secure Delete when emptying Recycle Bin.
- Fixed bug in Secure Delete with 0 byte files.
- Fixed bug in Uninstall Tool with non-standard entries.
- Resource file loading optimizations.
- Updated Windows Live toolbar cleaning.
- Added Bulgarian translation.
- Updated several translations.
- Updated installer engine.
- Minor bug fixes.

Download: CCleaner 1.40.520 
Link: http://www.ccleaner.com