You're very welcome.
Unless there was some particular software you wanted that was bundled with the PC, try my suggestion first because it will work with the W8 product key encrypted in the BIOS. That is where the keys are now. No more stickers with W8 PC's.
Then you won't even need to buy recovery disks, and you will have a clean, bloatware-free version of W8.
As long as any hard drive you buy is the same or larger storage capacity as the one in there now, the recovery disks should work just fine.
If you decide to install a smaller drive like a solid state one, then most likely the recovery disks won't work, which is another reason why the file I linked you to is good.
You can install that on any size hard drive you want as long as it meets the minimum requirements to install W8.