%SystemRoot% and C:\WINDOWS in path

I have noticed my path variable includes references to the Windows directory in both %SystemRoot% and C:\Windows forms.

e.g. there exists a %SystemRoot%\system32 and a C:\Windows\system32 in the path variable.

• Is it safe to remove one of the forms, and if so, which is it preferable to remove?
• Is there any performance gain (no matter how minor) to be obtained from doing so?

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