MacBook not recognising hard drive anymore

[Loved]

Hello,

I had to reinstall my OS as I was having several glitches. All of the glitches are now fixed after reinstalling, but there's now a problem where my computer wont recognise my hard drive.

My hard drive was working fine before I reset my computer. But, now, after resetting, it's not working? Same version of the OS running as before.

Could someone please explain how I could go about fixing it?

Thanks!

 

[Macman45]

Do you mean an external drive? I assume so as you must have installed the OS to a drive someplace....Can you be a little clearer?