Ctrl and Alt keys are not responding anymore

Hello,

I'm writing to you because my ctrl and alt keys are no longer functioning as they used to (thank my little brother who must have been playing with my keyboard...).

Usually, when using a keyboard shortcut (ctrl+C, ctrl+V, alt+133, etc.), it's the ctrl and alt keys on the left side of the keyboard that are used.

However, these keys are unresponsive while the ctrl/alt keys on the right side have started to work (it seems to me that normally, the alt gr key and the right ctrl key are not used for basic keyboard shortcuts, but I could be wrong).

As a result, I have to use my keyboard shortcuts only with the ctrl/alt keys on the right, which, as you will agree, is very uncomfortable for a right-handed person (since I have to let go of my mouse each time).

How can I reverse the configuration of the keys and reactivate the ctrl/alt keys on the left?

Thanks in advance!

P.S. I want to clarify that this is not a language configuration issue for the keyboard in any case.

<config>Windows 7 / Chrome /config>