Here are the essentials points for Quickbooks 2018 download on your system. For Mac, please ensure you have at least Mac OS Xv10.12 (Sierra), Mac OS Xv10.14(Mojave), and 10.13 (High Sierra). Check your internet connection; it should have strong signals. It's good to have Intel Core 2 Duo for multi-user windows. Future, the disk space required is 250 MB.