Prevent Hard Drives and External Storage from powering down
Some internal and external hard drives use power saving functionality to power down (go to sleep) after some time of inactivity. That's beneficial for power consumption but it adds a spin-up delay when the drive is accessed.
Solid State Drives are not affected by this as they use different technology but if you use platter-based drives you may have noticed that they won't react immediately to user commands after inactivity.
I published a guide back in 2009 that showed you how to disable or bypass the power saving mode of external hard drives. The guide is still valid and highlights how you can change Windows Power settings or use third-party tools to prevent the powering down.
The downside to this is that the drive consumes more power, the positive effect that it can be accessed right away without spin-up period.
Prevent Disk Sleep
Prevent Disk Sleep is a freeware for Windows that does the same thing. It supports all hard drives connected to the machine and will simulate activity on selected drives by writing to the disk in select intervals.
You need to install the application before it becomes available; the installer is clean and the installation process is straightforward. Prevent Disk Sleep is compatible with all versions of Windows from Windows XP to Windows 10.
The program displays all available options on start. It lists the connected drives, internal and external, and below the list of drives preferences. Just check the drives that you want to prevent from going to sleep and hit the start button to run the app. You can change the interval which is set to 30 seconds in the program interface and change the name of the text file as well there.
Prevent Disk Sleep writes a plain text file to the selected disks to simulate activity. The disk won't enter the power saving sleep mode because of the activity so that it can be accessed right away when needed.
You may want to experiment with the selected interval, for instance by incrementing the interval by 30 seconds until the disk enters sleep mode. The previous interval may be ideal then to prevent sleep mode.
Prevent Disk Sleep is a simple but very effective program for Windows that blocks hard drives from entering power saving modes. The program needs to run in the background but its memory usage is quite low. It used less than 2 Megabytes of memory while running on a Windows 10 Pro system.