Why does my IMac reboot when I try to reinstall operating system

Question

Why does my IMac reboot when I try to reinstall operating system

I am trying to re-install my o.s. due to a problem . I have a 2008 and was running Yosemite for a while before my computer started rebooting on its own.I tried to run hardware test from original software disc but it locks up and will not run so I tried to repinstall the original operating system from disc. I got as far as formatting the drive but after the disc test was performed and the install process beganthe computer will either lock up or a message will come on saying it needs to re-boot. Once it reboots you have to start over again. I also have a Snow Leopard startup DVD but it does the same thing. This is my first Mac and this is the first problem I have had,so I do not know much about this.Any suggestions? Thanks, William

iMac

Posted on Feb 9, 2015 6:38 PM

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Answer 1

Eric Root

Level 10

684,027 points

Feb 10, 2015 7:34 AM in response to williamfromardmore

When booted off the DVD, original or Snow Leopard, go to the Utilities menu and run Disk Utility Repair Disk and Repair Permissions. If the disk is okay, try to install the OS again. If you still have problems, insert disk 2 of the original disks and restart holding down the D key and run the Apple Hardware test.

Apple Hardware Test doesn't catch everything, so even if it doesn't find a problem, you could have one.

Apple Hardware Test

Apple Hardware Test – Invoke and Interpret

Apple Hardware test – How to run and interpret (2)

Apple Hardware Test - Using

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Answer 2

Feb 19, 2015 3:34 PM in response to Eric Root

Thank you for the help. I ran repair disc and it said disc appeared to be ok but I can not run repair permissions because it is grayed out. Is there a way to enable it?

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Answer 3

Eric Root

Level 10

684,027 points

Feb 20, 2015 6:46 AM in response to williamfromardmore

Try re-installing. Hopefully i9t will work this time.

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