There are a ton of Sysinternals tools for troubleshooting and non-troubleshooting. If you want a collection of troubleshooting tools (very helpful if you’re working outside your PC network at a friends house, a business you’re helping/working for etc.), then you can download the Windows Systinternals Suite. This suite is regularly updated and currently sits at a whopping ~13MB:
Download Sysinternals Suite
Download Sysinternals Suite |

Ever use the Windows Calculator and, because you’re too lazy to write numbers down or commit them to the calculators “memory”, end up with 5 instances of the program running—each with their own numbers that are easily forgotten? Or is that only me?