Before installing, verify your Mac meets these minimum technical specifications: How to download and install macOS - Apple Support
Once the .dmg file is downloaded, follow these steps to place the actual installer in your Applications folder: mac os x yosemite 1010 5 download dmg link
: Download OS X Yosemite 10.10 directly from Apple's servers. Before installing, verify your Mac meets these minimum
If your Mac originally came with Snow Leopard (10.6) or Lion (10.7), Yosemite 10.10.5 is an excellent upgrade. Yosemite 10.10.5 is an excellent upgrade.