The Sysinternals Suite contains a large collection of individually executable PC troubleshooting utilities by Mark Russinovich from Sysinternals (which was recently grabbed by Microsoft). Mark Russinovich the guy who revealed to the world that Sony CDs had that nasty rootkit installed has made available a single suite of tools for download. These tools are a must have for every single windows developer.
The Sysinternals Troubleshooting Utilities have been rolled up into a single Suite of tools. Download it here.