MacOS – Yosemite keeps asking to install Java runtime, while it’s installed

I did some more research and finally found some things out:

• I have the Logitech remote software installed, and when launching it, it brings up the prompt, but a slightly different one. So, I know I have a few Java apps installed, but this was happening without me launching something
• My actual error was related to a Facebook chat thing I had installed a while back, that I never put on my iMac. It was named 'com.facebook.videochat.[username].plist', and was in my ~/Library/LaunchAgents directory.
• I actually came across this question (asked after mine) when searching for the only Java information I found Console.app:

  8/31/12 6:44:23.606 PM Download Java Components[7588]: com.apple.message.domain: com.apple.java.usage2.DownloadOnDemand.complete com.apple.message.result: failure com.apple.message.signature: install_canceled com.apple.message.domain.version: 12A269

• I would recommend checking your ~/Library/LaunchAgents directory first, and you can easily grep for java by doing: cd ~/Library/LaunchAgents and then grep -i "java" *.*. This searches for the word java (case insensitive) in all files in that directory. Thats where I found the reference to the Facebook videochat plist.

Lion / Mountain Lion's recovery is only present on hard drives that have the system already installed. Internet Recovery (likely what was used with your Dad's Mac) is only built in to newer systems that shipped with Lion or Mountain Lion. Apple support page documenting this

In your situation I think your best bet would be to download Mountain Lion using your MacBook Air, build a Mountain Lion installer disk using the application below, boot to the install disk/drive by holding option while powering on your Mac and selecting the disk and installing as usual from there.

Lion Disk Maker

Hope that helps!