Partition failed to erase and now cant reinstall OS

[minch0111]

Hi

I tried to wipe an old late 2008 Macbook I have to sell on, however when I have went to erase the “Macintosh HD” its format failed and I now have an unmounted “disk0s2” that wont repair or erase. I cant erase the main hardrive as it says the disk0s2 cant unmount.

When I try the online OS installer it gets to a point where it asks where to install the OS and the only option is “Recovery HD” and that is greyed out

Could you advise on a possible fix for this
Thanks

 

[Honza1]

2008 MBP is very old, did you really run Catalina? This is Catalina forum...
For this old MBP it should be relatively easy. You need to download installer for whatever version on OSX/macOS you want to install and make USB bootable installer (google it, there are instructions on line). You will need working Mac to do this, though. Next you boot the MBP on this USB installer (check Apple shortcuts how to select boot disk) and format the internal drive while running off the USB and install new system.
Optionally, you can extract the drive from the MBP, put that in USB docking station, connect to Mac and format it from there. Then you can download installer on this Mac and try to install onto the USB ecnlosude drive from there. It gets bit complicated as you may have version issues - you cannot run installer of older system while running newer system, I believe.
At the end, having USB bootable installer is best. 8GB usb sticks are cheap today and it is may be hour work on working Mac to make it.

 

[minch0111]

Apologies, its running Yosemite my current Macbook Pro is running Catalina, thats why Ive mistakenly posted in here. Please move if necessary.
Thank you for your reply, I will try that