Ever wonder what happened to suddenly fill up that massive hard drive? Well, it probably didn't happen "suddenly", but these tools will help you locate the "space hogs" and duplicates.

File Management

Disk Space Fan - Graphical depiction of folder usage with double-click drill down

Duplicate Cleaner - Finds duplicate files based on your filter parameters

Space Sniffer - Quick way to check your disk usage without installing a program

SyncToy - Quick & easy way to compare & sync two folders. 32 or 64 bit versions.

FreeFileSync - Think SyncToy with more options & faster

Allway Sync - More robust sync tool, but free version only syncs 7 folder pairs