Help with Late 2009 iMac


macrumors newbie
Original poster
Sep 14, 2018
Dhaka, Bangladesh
hope I don't bore you with my rambling.

One of our relatives gave away their discarded imac to us and said that we can keep it if we can make it work again. It wasn’t booting up. We sent it to a local repair shop. There are no authorized mac shops here in Bangladesh. Anyway, the people in the repair shop probably never worked with an imac because they couldn’t even figure out how to open the damn thing. After I looked up the process and relayed it to them they were able to do it. So after a few days they tell my dad that they couldn’t install the mac os so can they install windows instead. I should let you know that I had absolutely no idea it was possible to use windows in a mac so I told them they should try to install macos but go for windows only if that’s not possible. In the end they still were unable to do it and they sent it to me with windows 10 installed. It wasn’t a perfect run; windows update wasn’t working and I’m pretty sure they installed a pirated windows copy. Oh and by the way, we are using our wired pc mouse and keyboard to operate the imac: the apple ones had like 101 pencil batteries and we couldn’t be bothered to buy batteries to use it.

Anyway, we used the imac for like 2 days and problems started to arise. Like I said, Windows update didn’t work. I also noticed that I couldn’t update my google chrome browser. Then all of a sudden all the usb ports stopped working: my keyboard and mouse lost power. So I rebooted the computer and since then windows isn’t booting up properly. The OS gets stuck in the windows logo. After rebooting some more a screen shows that widows isn’t booting up properly and so they give me some options to repair the os. I used the option to reset my pc but it’s still not working.

Before I ship it back to the repair shop I wanted to try some things for myself. First of all, I don’t want to use windows on this imac in the first place. Like duh why would I use a foreign OS in a mac computer!! I searched online and I hear something about bootcamp? But this method is used when a working macos is already installed. Who knows how the repair people installed windows here when they couldn’t install mac first. I don’t even know if there’s a copy of an existing macos in the harddrive somewhere.

So can anyone help me remove the windows os and install a fresh copy of macos in my imac late 2009. I have wifi in my home so I can install it directly from the internet. Do I need my mac keyboard and mouse for this? Also mind it: this wasn’t originally my computer so I don’t have any apple account or anything. Please help.

EDIT: Ok so choosing a system restore point worked and I can boot my windows again. But I still want to delete the OS and install mac.

EDIT 2: This is the exact model of our imac: Corei7, 4bg ram 1tb HDD and AMD mobility radeon graphics. So maybe it won't run smoothly with the latest macos. But I don't need the latest, I just want the computer to run an appropriate macos


macrumors newbie
Nov 30, 2003
Try to boot into recovery mode. Press command R when you here the startup chimes and hold until it chimes again. Once in you can use Disk Utility to format the drive then install OS X. The original problem your relative had could have been Hard Drive failure, if so you'll need a new drive and thermal sensor kit, HD replacement on the 27' 09's is not that bad and there's plenty of information about how to out there.

Good Luck


Oct 31, 2017
It appears as if the computer is operating fine and all you need is a fresh install of the operating system. Did your relatives happen to provide you with the original media that came with the computer? If not you'll have to locate a copy of the software. That model originally shipped with OS X Snow Leopard (10.6.2). For $19.99 you can order media directly from Apple:

This is version 10.6.3 but, and this might be an issue, it might be an upgrade version (I have a couple of these and they're both upgrade versions). Check with Apple to ensure you can install on a computer which lacks a copy of OS X installed. There's also Lion and Mountain Lion available from this page. Once you have a copy of OS X installed you can upgrade to the current (10.13) version at no cost.

If you're unable to purchase from Apple you'll need to find a copy of the OS. Unfortunately this model does not support Internet Recovery.
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