I can't restore my iMac Mid 2010

[mac23456]

I have an iMac 21.5' Model and I have recently found the install discs (Original OS X Snow Leopard) and I can insert the DVD but after about a minute it ejects. I have an old hackintosh, as well, and I have the same problem with that, unless I am booted into OS X Snow Leopard on that device. (My Mac runs High Sierra) It won't show up in the boot menu on either device. I have no idea what has happened.

Thanks in advance!

 

[Fishrrman]

Does your iMac have the capability to boot to INTERNET recovery?

This is NOT the same as "the recovery partition".

Command-OPTION-R at boot.
If you're using wifi, you'll need your wifi password.
It takes some time for the internet utilities to load.

BE AWARE that internet recovery first became available to Macs in 2010 or so.
Your iMac may or may NOT be capable of it.
You need to TRY it to find out.

Internet recovery offers a way to install the OS directly from Apple's servers.

A question:
WHY do you want to re-install the OS...?

 

[mac23456]

Thanks for your quick response! To answer your questions:
It can use internet recovery, and I know how it works. Is it not Command-Shift-Option-R?
I want to reinstall the OS as I my family no longer use it and I want to remove al the junk so it is in a condition for work.
However, my internet is slow, and it would take some time to load. I can plug my laptop in with ethernet, but not my iMac.

 

[Fishrrman]

Try Command-OPTION-R first.

 

[mac23456]

OK, I have booted into internet recovery, and it has installed Mac OS X Lion.
Thanks for your help.