CCleaner 좋더군요.

저희 회사에서 배포하는 장비의 윈도우시스템 하드드스크 복구 이미지를 만들때,
압축효율을 높히기 위해서 빈공간을 지워주는 툴을 찾다가 우연히 발견했는데
윈도우용 "쓰레기 청소" 소프트웨어 입니다. 불필요한 캐쉬 레지스트 정리를 해줍니다.
하드디스크의 빈공간도 지워주는 기능도 있습니다만,
하드디스크를 교체하거나 하기 전에는 일반인들은 크게 쓸일은 없을겁니다.

설치할 때 야후툴바만 설치하지 않도록 신경만 써주면 나머지 사용하는데는 크게 문제가 없더군요.

게다가 라이센스가 매우 착합니다.

이하 라이센스 발췌...

By using or distributing this software (or any work based on the software) you shall be deemed to have accepted the terms and conditions set out below.

Piriform Limited ("Piriform") is making this software freely available on the basis that it is accepted as found and that the user checks its fitness for purpose prior to use.

This software is provided 'as-is', without any express or implied warranties whatsoever. In no event will the authors, partners or contributors be held liable for any damages, claims or other liabilities direct or indirect, arising from the use of this software.

Piriform will from time to time make software updates available. However, Piriform accepts no obligation to provide any support to free licence holders.

Piriform grants you a limited non-exclusive licence to use this software for any purpose, including commercial applications and redistribute it freely, subject to the following restrictions:

1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software.
2. You must not alter the software, user licence or installer in any way.
3. This notice may not be removed or altered from any distribution.
4. You may not resell or charge for the software.
5. You may not reverse engineer, decompile, disassemble, derive the source code of or modify [or create derivative work from] the program.
6. You must not use CCleaner to engage in or allow others to engage in any illegal activity.
7. You may not claim any sponsorship by, endorsement by, or affiliation with our company.
8. You acknowledge that Piriform owns the copyright and all associated intellectual property rights relating to the software except to the extent that the software includes identifiable separate components originating from the Yahoo! Toolbar.

This software licence is governed by and construed in accordance with the laws of England and Wales and you agree to submit to the exclusive jurisdiction of the English courts.