WinRar works better for Navcore installations as you can preserve the file/ folder information without any messing about, its a single one shot install and the WinRar app ensures that files that need to go in to specific folders and sub folders are correctly located.
Win Zip on the otherhand isn't something I trust for doing this as I have had issues in the past with all the files being dumped in to the root of the device resulting in a few hours of messing around to resolve what its done - Mike