What can i do now to fix it all ?

You might reboot so that any pendmoves get deleted then reinstall

Or pskill perl then reinstall

Or Uninstall (even if you have to rm -rfv C:\strawberry ) then reinstall

I guess i should have used something like perlbrew to avoid this problem.

Nope, perlbrew is linux only, and some like perlall better than perlbrew

This is purely strawberryperl installer bug territory -- maybe try the .zip only installer

An installer should be able to detect any conflicting perl.exe processes running, warn about installing in an old directory, overwrite said directory and all files successfully or warn you, ask to add shortcuts, ask to modify registry settings (add to %PATH%, add ftype/assoc )... but I've not used strawberry in a while