Installation program recommended for XP/Vista/7
Most recent: Disk Cleaner version 1.8.1795
Pick this download if you want the latest version with the newest options, but with the possibility of encountering bugs.
Stable: Disk Cleaner version 1.7.1645
Pick this download if you want a more thoroughly tested version with less options, and a lower chance of hitting bugs.
Installation program recommended for Windows 2000 and earlier
Disk Cleaner version 1.5.7mirror #1 - sourceforge.net
mirror #2 - author's site