There are some keys on the keyboard, such as the caps lock and scroll lock keys, that can be annoying if they accidentally get turned on without you realizing it. When I found Keyndicate I thought it was pretty cool not only because it would indicate when one of those keys was pressed, but it also includes an option to “freeze” the current state of the keys so that they can’t be toggled.
The screenshot above provides an example of what it looks like with the caps lock and scroll lock keys turned on. There is a letter added to the System Tray icon for each of the keys that are on, and there would be another one for num lock if that was turned on. If the icon is too subtle you can even turn on the notifications to ensure you really know when the keys are toggled.
This is a very lightweight program that requires no installation, and uses less than 2MB of memory on my system. That means you can leave it running without it affecting the performance of your system.
Keyndicate Homepage (Windows only; 32/64-bit; Portable; Freeware)