Process Tamer - Freeware Microsoft Windows utility that monitors the CPU use of applications, alerts when they use too much, and reduces their priority to keep your PC fast.
WinDirStat - WinDirStat is a disk usage statistics viewer and cleanup tool, inspired by KDirStat.
Big Meter Pro - Big Meter Pro is a utility that monitors the disk and memory of your CPU.
TreeSize - TreeSize tells you where precious disk space has gone to.
AMD64 CPU Assistant - AMD64 CPU Assistant
SpaceSniffer - SpaceSniffer is a freeWare (donations are welcome) and portable tool application that lets you understand how folders and files are structured on your disks.