Free Windows tool No. 14: Process Explorer
The granddaddy of program monitors, Microsoft's Process Explorer is up to Version 15. If you've never used this tool, you've never seen what's going on under Windows' covers. If you have, this new version boasts new tricks and a much-needed makeover for the CPU and memory monitor. PE shows you all running processes and subprocesses, and with a click or mouse-over, divulges details about what's really going on. Want to know which program has a file locked? Curious about the origin of all of those svchost.exe programs running on your machine? PE also tells you everything about CPU cycles, memory usage, and I/O. Best of all, PE doesn't have an installer. It just runs, and runs well.