Cant reinstall startup disk on Mac?

[GaryBarlow]

Hi,

I had the dreaded question mark folder when I turned on my Mac and soon found out that my Startup Disk had mysteriously vanished.

Eventually I managed to get the computer started by installing a startup disk on an external hard drive which works fine but now I’d like to turn on the computer without the external drive plugged in.

Is there a way to reinstall the startup disk on the Mac?

I’m currently on version 10.9.5 but I used to be on a more recent version (it’s been a while since I’ve properly used my Mac due to personal circumstances).

Not sure what other info I need to give for anyone to usefully help me, but I can give more info as required.

Also apologies if any of the above is unclear but I do feel like I’m attempting to speak in a foreign language when talking about computers.

Thanks in advance

Dominic

 

[Cory Cooper]

Hello and welcome.

• Which exact model Mac?
• How much free space is left on the internal drive?
• Do you have a current Time Machine or other backup of your data?
• Did you have any other issues leading up to this issue, i.e. hanging, freezing, etc.?

C

 

[GaryBarlow]

Hi Cory, thanks.

The model is iMac, 21.5 inch, late 2013

When I check for storage in about this Mac it only shows two external hard drives, my backup drive and the one I used as a startup disc, is the internal storage shown elsewhere or is that a major part of my problem? Has my internal drive gone missing/broken?

I have a time machine backup yes, if I try to restore from time machine the only destination disk shown is the external drive that has the startup on, so I guess that’s part of the bigger issue that I hadn’t realised about my internal hard drive.

I don’t remember any issues but I remember thinking there’d been a power cut or surge or something, both the smoke detectors were playing their low battery sound even though they’re both mains powered with battery backup.

It seems I may have been asking the wrong question then, is it possible to recover my Macintosh HD drive?