Prior to installing and moving it to an external drive for safe keeping. InstallMacOSX.dmg if you need it in future, or you could just make a copy of the Install OS X El Capitan.app

The copy of the install app self deletes after installing El Capitan, so make sure you keep a copy of the To start the installation of El Capitan double click on the Install OS X El Capitan.app. You want to eventually install El Capitan on, that is for later.) The disk that you are booted to at the time. (If the installation window asks which disk you want to install to, you must pick You will find in your Applications folder, it should be 6.2GBs in size. That and an installation window will open, this does not install El Capitanīut converts the InstallMacOSX.pkg to the Install OS X El Capitan.app which When downloaded open to InstallMacOSX.pkg, double-click on This includes macs that have the potential to run El Capitan but have been upgraded to a newer OS.Ī mac that came preinstalled with an OS later than El Capitan will refuse to do the next bit. The next section can only be done on a mac that is capable of running El Capitan. This downloads InstallMacOSX.dmg to your Downloads folder. Go to Download OS and click on OS X El Capitan 10.11 How to get old versions of macOS – Apple Support If you do have an operating system on your mac and it is functioning then you can download If you have another mac then you can try downloading a newer copy of El CapitanĪnd create a bootable USB and try that one. Here's also a You Tube video of someone installing an SSD in a 2008 iMac (somewhat similar to yours).How did you make this USB bootable flash drive, those error reports look like This is just a standard hard drive replacement procedure (not an SSD swap)…but in steps 19-21 you can see what the temp.

Here's a procedure (link below) describing how to replace the hard drive in a 'Mid-2007' iMac. I think that your best bet (if you're super concerned).is to open the iMac up…and see what's in there.

The only reason why the fans would go crazy…is if the temp sensor hardware was damaged…and the computer received no reading. I don't think that the fans will go crazy…since the with less heat & lower temp., there will be no reason for the fans to go crazy.

2008 imac hard drive replacement