$inputDirectory = "C:\Users\creme\Downloads\Chess\to_clean_pgns\input"
$outputDirectory = "C:\Users\creme\Downloads\Chess\to_clean_pgns\output"
$pgnExtractPath = "C:\Users\creme\Downloads\Chess\to_clean_pgns\pgn-extract.exe"

Get-ChildItem -Path $inputDirectory -Filter *.pgn | ForEach-Object {
    $outputFile = Join-Path $outputDirectory $_.Name
    & $pgnExtractPath -C -N -V -7 -o $outputFile $_.FullName
}

This is the final scipt from ChatGPT
I could never write such a script without the help of ChatGPT
I wonder what to study and how long it takes someone can write scripts like this?

For user-friendly usage of the batch file, put a shortcut to the batch file in the Windows SendTo folder.

• Find a permanent home for the batch file, so SendTo always knows where to look for it. This can be anywhere that makes sense to you. One likely candidate is the same folder where pgn-extract is installed. So, move pgn-clean.bat into "C:\Users\creme\Documents\static\programs\bin".
• Create one shortcut for each set of pgn-extract options you commonly wish to run. For illustration, create one shortcut to remove comments, and a second shortcut to remove variants. (You can create shortcuts with different pgn-extract options according to your needs.)
  First shortcut:
  1. right-click on pgn-clean.bat and choose Create Shortcut.
  2. right-click on the shortcut and choose Rename, change it from "pgn-clean.bat - Shortcut" to
     'pgn-clean-C".
  3. Right-click again on the shortcut and choose Properties. In the Target field after pgn-clean.bat add a space followed by -C.
     C:\Users\creme\Docments\static\programs\bin\pgn-clean.bat -C
     Click OK.
  Second shortcut: Do the same three steps but use "V" instead of "C". To reiterate, this is just for demonstration purposes. You can use any pgn-extract options you like.
• Move the shortcuts you created into the folder "C:\Users\creme\AppData\Roaming\Microsoft\Windows\SendTo"

Now whenever you want to remove all the comments from a pgn folder, right-click on it, choose SendTo, choose pgn-clean-C. To remove variants, choose pgn-clean-V. Just keep in mind how pgn-clean.bat uses the clean sub-folder and skips any pgn files already in there. The way Windows shortcuts work is by constructing command lines (targets) and executing them. And "SendTo" puts your folder at the end of that command line, which is where the batch file expects to find it. pgn-clean.bat stops processing command line arguments after the first folder, so if you select multiple folders and use SendTo, only one of the folders will be cleaned.

Note that running the batch file this way, the command window closes at the end, because it has (and needs) an "exit" command. If you want the command window to hang around, there are different ways to accomplish that. Here are two:

1. Edit the shortcut Target, adding at the beginning cmd /K and a space.
   cmd /K C:\Users\crewe\Docments\static\programs\bin\pgn-clean.bat -C
2. Edit the script, adding a pause statement (just pause on a line by itself), just above the exit statement, like so:
   :PROC_EXIT
     echo %DATE% %TIME% INFO 0 exiting [%~f0]
     pause
     exit /b %errorlevel%

Updated the script for error 703 description.

By the way I asked the same question on talkchess.com

Someone gived me this script as exemple:

SET PATH=D:\bin;%PATH%

FOR %%F IN (%*) DO (
     pgn-extract -amerged.pgn -D -s -C -N -V -Z -Tr1-0 -Tr0-1 -Tr1/2-1/2 -lmerge_errors.txt -tstartpos.txt --fixtagstrings -w80 --minmoves 8 --nobadresults "%%F"
)
pgn-extract -Wuci -opedantic-clean.pgn -D -s -C -N -V -Z -lmerge_errors.txt -tstartpos.txt -w128 --minmoves 8 --nobadresults merged.pgn
DEL merged.pgn

He says that I could edit it a bit so I could do what I want.
But dousn't help me much becouse I'm an amateur.

I think your script wil much more helpfull once I get it to work, so thanks for the effort.

Jonathan003 wrote on 08/28/23 at 18:38:24:

Yes, and pgn-extract in a script is a good way to do it.

Jonathan003 wrote on 08/28/23 at 18:38:24:

What you are asking for is called "in-place editing". pgn-extract cannot do it, but a script can do it using a temporary file. However, it is generally considered a bad idea:
https://backreference.org/2011/01/29/in-place-editing-of-files/index.html
In your scenario, in-place editing is definitely a bad idea because all "unclean" parts of the pgn(s) will be lost, and in a worst case you may end up with an entire folder of zero-byte pgns, without any easy way to recover the originals.

That said, I wrote you a script that does most of what you asked. For any one folder you give to the script, it will run pgn-extract against all the .pgn files in the folder and save them to a (new) subfolder "clean". Options on the command-line before the folder will be passed along to pgn-extract, allowing you to keep or exclude anything that pgn-extract can keep or exclude. It's up to you to delete the originals and move the clean versions over. Beware, though -- Scid and pgn-extract handle a bad game within a pgn file differently. Don't expect cleaning with pgn-extract to give identical results to cleaning with Scid. Proceed with care, and verify your cleaned file(s) before deleting any original(s).

Caveat emptor: I tested this under Windows 10 using the latest 22.11 version of pgn-extract, but afterwards I made some cosmetic edits to the script before posting here (adding comments, removing my username, etc.). And I did those edits under Linux, without retesting. It should work as-is, but no guarantees.
Edited: