Windivert is used by NeoLoad for WAN emulation and it is sometimes seen by antivirus as a threat since it can modify the data at network level.

Usually the way to go is to add an exception in the antivirus so it does not see it as a threat. You need to check with your IT team knowing that this tool is used by NeoLoad for a specific purpose.

That being said WAN emulation is optional so even if the antivirus removes the Windivert files it won't impact the use of NeoLoad. But obviously you will not be able to use WAN emulation in your population settings.