What a drive light tells you
Desktop cases used to have a small lamp that flickered whenever the hard drive was busy. It answered a question nothing else on screen does: is the computer actually doing something right now, or is it stuck?
Most laptops and many modern cases dropped that lamp. When the PC goes sluggish, the fan spins up or a program stops responding, there is no quick way to tell whether Windows Update, an antivirus scan, indexing or a sync client is working the disk in the background.
With the lamp in the notification area, the answer is always in the corner of your eye. A solid glow means something is hammering the drive; a dark lamp after a long copy means the writes have finished.
How to get an HDD activity light on Windows
HDD Light puts a drive activity lamp in the notification area next to the clock. It takes a few steps to set it up the way you want.
- Start the app and the lamp appears in the notification area.
- If Windows tucks it behind the ^ arrow, follow the window's pointer and use the Taskbar settings it opens to keep the lamp on the taskbar.
- Choose what the lamp shows: reads and writes, reads only or writes only.
- On the front panel, click a drive's lamp to choose whether that drive lights the one in the notification area.
- Turn on Start with Windows so the lamp is waiting in the notification area every time.
Telling disk reads from writes
The hard drive activity light can be a single red lamp that glows for any work on the disk. Split the colors and reads glow green while writes glow red, so you can see which way the data is moving.
You can also narrow the lamp to reads only or writes only. Watching writes alone, for example, shows you when a long copy to a backup drive has actually finished.
Tuning the lamp so it lights for real work
Windows writes a small trickle to the disk all the time, which would keep a sensitive lamp lit constantly. Five sensitivity levels, from every byte up to 4 MB/s, let the lamp ignore that hum and light only for activity worth noticing.
The disks are checked 10 times a second, so the lamp keeps up with the work as it happens. An afterglow of 0 to 500 ms holds the light for a moment after a short burst, so a quick write is still visible.
A hard drive activity light for each drive
One lamp can cover every drive, or you can turn on a lamp for each drive, each marked with its letter. Hovering the lamp shows each drive's read and write speed.
The window shows a front panel with a live lamp, transfer speed and 60-second trace for every drive. A USB stick or SD card shows up there as soon as you plug it in.
