Windows 10 How to identify which process accesses the optical drive?


New Member
Jun 28, 2022
After inserting a Blu-ray data disc (BD-R), an unknown background process accesses the disc even when I am doing nothing. It even happens when deactivating the real-time protection feature of Windows Defender.

Existing tools such as the task manager and the third-party tool "Process Hacker" are unable to display I/O transfer rate on optical discs.

How can a process constantly accessing the optical drive be identified?

More detailed observations:
On two Windows 10 computers I have tested, after inserting a recordable Blu-ray disc with UDF 2.60 live file system and a few thousand files, the disc can be browsed inside Windows Explorer about a quarter minute after inserting the disc, as normal. However, the moment the disc is opened in Windows Explorer (File Explorer), something in the background starts reading data from the disc and keeps reading for several minutes. The drive keeps spinning during that time and its I/O indicator LED keeps blinking. After that time, it stops reading from the disc in the background and data can be read and written again without interference. The duration of this mysterious background process appears to correlate with the number of files on the disc, taking longer on discs with a higher number of files.

This makes it hardly possible to read data from the disc or write data to it, since this mysterious process interferes. It also causes Windows Explorer to stop responding, showing "(not responding)" in the title and the white mist that fades in and covers the window. When trying to read or write data, the drive's laser lens has has to alternate between both the location the user is trying to read from or write to and the location this mysterious parasitic process is reading, which makes both extremely slow; under 100 KB/s. In other words, both processes "fight" for the laser lens like wild boars. It's detrimental to both participants, creating a lose-lose situation.

The task manager does not show which process it is, since it can not show the I/O usage on optical media.

I have temporarily deactivated Windows Defender's "real-time protection", which I thought might cause this, yet it still happens. I tried taskkilling explorer.exe to see if it stops, but it didn't.

Does anyone have an idea what the source of this problem might be? Could it be some equivalent to Android's media scanner? In the early 2010s, bugs in the media scanner sometimes caused significant battery drain on Android devices. Does Windows have such a thing as well? And most importantly, how can it be prevented?

The closest guess would be that it loads the file tree in memory for search indexing, but that still does not explain why it takes several minutes for a few thousand files, which is similarly as slow as the directory listing of Media Transfer Protocol (MTP), except it also does so unsolicitedly.
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