So, to be
absolutely clear, OS 10.10.5, ie, Yosemite, was already installed on the machine, and when you downloaded El Capitan, OS 10.11.1, you just upgraded from OS 10.10.5 to OS 10.11.1. Is that correct?
Also, just saw your latest post, where you state "I try to run a diagnostic and i get an error in there also....?". Again, how
exactly are you trying to do that? What diagnostic software are you using to do that?
Also, what do you mean by "no recovery"? If there is no Recovery HD partition on your internal drive, which happens sometimes, you have some challenges. When you say "i am trying to get a Yosemite os to install", how
exactly are you trying to accomplish that? It is important that you provide us with the things you are trying, in a detailed manner. With all those details, we can help you better.
I have never tried the following approach, where a different OS is already installed on the drive, but I suspect it could work. Also, do you have anything
critical on your internal drive that you can't live without? From one of your earlier posts, it seems like you
must have Office 20111 and Adobe Creative Suite. Hence, you would need to at least copy those original applications somewhere. If you do not have an external drive, then maybe consider purchasing a Flash Drive. Not sure how big of such a drive you need, as they come in sizes of 8 gig, 16 gig, 32 gig, 64 gig, and 128 gig. Again, you will need to determine what stuff you
absolutely must have before you proceed with my explanation below. Don't worry about Apple software, as the OS will install all that. Finally, make sure you have the latest version of the Install OS X Yosemite file someplace. That is typically in your Applications folder, but it would be best if you have a copy of it also (maybe on the flash drive).
OK, assuming you have that Install OS X Yosemite file someplace, there is a third party application you can use to create the Recovery HD partition. It is available from here:
http://musings.silvertooth.us/2014/07/recovery-partition-creator-3-8/
Just click on the link that says "Recovery Partition Creator 3.8". I have previously used it a couple of times, and it works flawlessly. After you download and install it, and then launch it, you will need to tell it where the Install OS X Yosemite file is. I believe this will still work, and give you the Yosemite version of that Recovery HD partition, even though you have OS 10.11.1 installed on your drive.
Once that is installed, you can boot to it like I described earlier, and then use Disk Utility there to 1) analyze the internal drive to make sure it is OK, 2) Erase, Format, and Partition (most likely if you only need 1 partition (as most folks do), the drive will already have 1 partition through the formatting), and 3) then perform a clean installation of OS 10.10.5.
After that is done, re-boot your machine (hopefully that will work), and then you can install the critical files/programs, etc. from the flash drive.
In any event, you'll need to first provide succinct answers to the questions I asked above, before proceeding. Also, in the future, whenever you are considering an OS upgrade, you should 1) insure that your applications will work with the new OS and/or new version of a current OS, 2) make a backup
before applying any kind of OS upgrade, and 3) perform some disk maintenance/cleanup, again
before upgrading. Doing that will definitely minimize any headaches. And, consider purchasing a more robust disk maintenance/repair program. Disk Utility is OK, but there are better choices, like Disk Warrior and TechTool Pro.
