Solved Reinstall Windows 8 after factory repair?

I upgraded the pre-installed Windows 7 to Windows 8 on a computer under warranty. The computer developed a defect that needs a factory repair and I will be using the recovery facility to restore Windows 7 before the computer is collected.
On return its return will I be able to use the same installation disc and product key to upgrade again?

Try it and see if it activates first.

If not, you may need to call MS and explain to get activated.

I don't think you will any difficulty. MS are desperate to try and get people to use this thing.

That's two or three weeks in the future! Thank you for your response.

If it's a hardware problem, do an image backup then when you get it back do an image restore.