Copy écran impossible avec IRFANVIEW ? problème kamo?

Well that tells you that whatever the problem is then it isn’t being caused by Kamo.

Try running the Windows Disk Clean up, using the ‘Clean up System files’ option.
It may take a while.
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Then:
When was the last time that you did a ‘Restart’ of your device?
Not a Shut down or a Hibernate but a Restart.
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If it’s been a while or you can’t remember then do one now.