TrainFan90

Just upgraded to high sierra and it's running like a dream. I installed macs fan control and it took care of the fans running at full speed.

Success!!! I finally was able to install mac os Lion with this dmg file and transmac.

alright, I can confirm that the late 2009 mac does support booting from usb. I just tested a memtest86 stick and it showed right up and it's running memtest86. So I guess I was doing the mac os bootable usb wrong. Yeah I'm going to try using my friend's actual mac to create the bootable usb.

Well one of my friends has one, I would have to make a trip to their house to use it

Could you tell me how?

I thought I did mention you in the last comment but I don't have access to a running mac or else I probably would've figured it out by now

I cannot get this damn thing to install mac os. I've tried everything I can think of. I don't have access to another mac before catalina, and every attempt I've made to use transmac to create a bootable usb drive has failed. When I get into the boot menu, the usb never shows up. Is it a bad dmg? I tried the Sierra and el Capitan dmg files directly from apple's website https://support.apple.com/en-gb/HT211683 no luck.

is that fixable with a fan speed app?

What it still work without this?

Already ordered a Samsung 860 evo

Ok it's definitely the late 2009 27'' version so High Sierra

does the early 2009 imac also come with the same specs and size?

No but my friend does

One of my friends gave me a 27'' 2009 imac that they didn't want anymore and it came without a hard drive. I tested it with a windows 10 hard drive and it actually works pretty well, so I was wondering if I can install mac os on it. I know it won't support big sur or catalina but maybe high sierra? It has an i5 750, 8gb ram, and a radeon hd 4850 If I can, how? I don't have much experience with macs