The Swiss Army Knife for Your PC

Great article at Lifehacker on Windows maintenance tools that anyone wanting to run a healthy PC should have installed.

Apart from CCleaner, Revo Uninstaller, Auslogic Disk Defrag, and Spybot – Search & Destroy, I would also add some in case virus/malware/spyware removal is required. RootKitRevealer, Ad-Aware, ATF-Cleaner, Avenger, HijackThis and Trojan Remover.