The first software you install after you have setup the operating system is Anti Virus. Why? A new machine is bare to to internet. Nothing to stop malware and viruses from infecting your computer. Many software installations require you to go to the browser and install from their server. Part of the Anti Virus install is making sure all the updates are complete.It may take a few passes to do this. The important part is to protect your computer as well as yourself. Some malware can steal your data and your wealth (especially if you do online banking). This goes for Macs as well as PCs.