Question: To add subtitles to a single file I use the following command:

`mkvmerge.exe -o g:\movie01.mkv --default-track 0 --language 0:pl movie01.mkv movie01.srt`

**Where:**

`movie01.mkv` is the name of a video file

`movie01.srt` is the name of a subtitle file (it is always the same as the video file)

`g:\movie01.mkv` is the output file

**How do I run the above-mentioned command for every file in a directory?**

Answer: 
No. Most likely is not (of course you can do a virus check to make sure it isn't a replacement).

Windows has two variants of the `explorer.exe`: one for 32 bits and one for 64 bits use. It is the Windows shell executable. There is nothing wrong in having two versions hanging around.

Most likely a shell plug-in or something like that caused the massive CPU load.
So, as it turns out, it was a virus.

I rebooted my Windows after scanning it to find that it had triggered a `diskpart` on my machine, wiping my hard drive.

I took it to the local computer store, and the guy that worked there said that it would of caused it. (He somehow managed to check logs that were on my motherboard.)

Virus Total said it was a virus and Malwarebytes said it was a virus, but I couldn't remove it.

Ah well, i'll just switch to Linux then :D