Gary McCoy
Thanks to all for the advice.  I have another question:
 
The computer in question was purchased as a refurb.  Windows was installed on a partition, and did not include a Windows 7 CD.  So, will I have to buy Windows again?

Make and model?
Do you have the Windows serial number sticker on it?
What is the full version name of Windows 7 ? Pro/Home/Ultimate or whatever...
nb Once you've installed you can probably update to windows 10 for free afterwards, you might even be able to update directly to Windows 10 (however I have no idea of the method right now, it's all new stuff to me right now).
You should certainly consider hopping straight away to Windows 10 afterwards before you install any apps assuming drivers are compatible. Normally I wouldn't recommend it but it will probably save you some agro later on.
 
Ta.

That's a fine question.  Laptops and desktops these days seem to come with a separate Recovery partition, for restoring the Windows partition to its original factory state, but that certainly would not help if the drive itself is toast.
 
If there is any way to contact the selling company/party, perhaps they could give you the product key associated with your computer, and then you could simply enter that one again and be OK.
 
Bob Bone