Restoring mid 2012 MBP for sale

[Mynameisbob]

Hello,
Id like to sell my mid 2012 MBP. Unfortunately it’s my first time reinstalling OS systems etc so I didn’t set up a bootable flash drive before I backed up my files and erased the disk (and I don’t know anyone that has a Mac I can borrow to create one!)

I’ve tried to access internet recovery to reinstall either Mavericks or upgrade to Sierra from there but control + R upon restart just brings me back to utilities.

Is there a way to install a fresh OS from a flash drive with simply the software dmg file or am I a bit screwed?!

Thanks.

 

[IngoX]

but control + R upon restart just brings me back to utilities.

Use Option-Command-R for internet recovery for latest possible macOS, Catalina 10.15 for a 2012 MBP.
If that for some reason doesn't work try Shift-Option-Command-R for the os that came with that model, 10.8 mountain lion and update from there.

How to reinstall macOS - Apple Support

You can use macOS Recovery, your computer's built-in recovery system, to reinstall the Mac operating system. Reinstalling macOS doesn't remove your personal data.

support.apple.com