You need a destination drive (or a virtual disk) that is equal to or larger than the original partition captured in the .rdr file.
Below is a guide on where to find these files, what the .rdr format entails, and how to safely install macOS High Sierra. Understanding the .rdr File Extension download macos high sierra 10.13.5 image file -.rdr-
If you have a compatible Mac, you can download the full installer directly from the Mac App Store You need a destination drive (or a virtual
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