Over the past few years I’ve written some useful tools:

• Process Hacker: A free and open source process viewer, more powerful than the default task manager and Process Explorer.
• WJ’s Backup: An incremental backup program for Windows.
• Empty Standby List: Empty working sets, modified page list, standby list, and priority 0 standby list.
• PAE Patch: Allows you to use more than 4GB of RAM on 32-bit versions of Windows. Supports Windows Vista, Windows 7 and Windows 8.

Also see Other utilities for small pieces of code and other tools.