TrayStatus is a simple tool which can display the status of various PC keys, as well as a hard drive activity indicator, in your system tray.
If you've used a notebook without a Num Lock or Caps Lock indicator light then you'll know how annoying this can be. You don't have to live with the issue, however: just install TrayStatus and it'll add appropriate system tray icons for you, highlighting these whenever Num Lock or Caps Lock are active.
And that's not all. The program can also display the status of your Scroll Lock, Alt, Ctrl, Shift and Windows keys (these are all optional, though - you get to choose what you'd like to see). And there's an even a hard drive activity indicator, which flashes when the drive is busy, and displays the current read and write speeds in a tooltip.
TrayStatus does have one or two minor issues. It grabs a little more RAM than we'd like, for instance, around 9MB (not much in the scheme of things, but it could be less). And it uses separate icons for each status, which while making things very clear, can also leave you with a packed system tray, and so less space on the rest of your taskbar. Still, if you only want to monitor a couple of items this won't be a problem, so try TrayStatus for yourself and see what you think.
What's new in 4.0 (Changelog)?
Change: Added a Triggers feature for automatically toggling caps/num/scroll lock keys
Change: Added an option to customize the colour of the drive letter overlays for Hard Drive Activity indicators
Change: Added an option to use separate indicators for each logical drive letter instead of each physical drive
Change: Added a 'Fix Performance Counters' button in the Settings window
Change: More languages included
Fix: Double-clicking a tray icon now correctly toggles that key
Fix: Restoring settings now uses the custom backup path when it's configured
Fix: Resolved an issue that caused the tray icons to get moved around, or moved to the overflow constantly
TrayStatus is definitely a versatile keyboard monitoring tool, although whether it's really a good idea to fill your system tray with status icons is another question