How Can I restore my computer back to factory new condition?

How can I restore my new (used) Dell laptop computer back to factory new condition? It had windows 10 put on it but originally, was windows 7. I tried to get F8 to open up so I can run the restore process - but it stubbornly refuses to do so. In fact, only F2 and I think - F12 - opens up when I press those F keys. Don't worry about my backing up files I wanted saved - I already did that to a flash drive. I read and listened to advice online on how to do the restore process - but no luck, so far. The demonstrator's computers were different from mine.

I ran the recovery process I saw in the Control panel, under the heading, "Backup and Restore (WIndows 7) since I couldn't get to the one that does a factory new one. After it was through, I see only one program listed in programs in the Control panel. Odd. But the blue bar in my PC shows it looks as full as before, if I remember right.

I am not able to get online any better than I had been before the process. I'll appreciate if you can help me figure out how to get that restore back to factory new condition - running.

It's Windows 7 that you want to return to??

I'd think a Dell with Windows 7 would have had a built-in factory recovery partition of some type.

But that may have been wiped out by the Windows 10 installation.

I assume you personally did not put Windows 10 on it? Who did?

Normally you have a BIOS option to run Factory restore.
What brand and model is the laptop?

Thanks so much for all the good advice on how to re-install windows 10! i didn't see a reply button, so have replied here. How do I find a way to reply to those who respond to my posts in here? Thanks.

There is about 99% chance the factory restore partition is wiped out or unusable at this point. To return to factory condition you are most likely going to have to purchase the restore disc from Dell.

These may be some options to consider:

Reset Windows 10
Custom Install Windows 10
Clean Install Windows 10
Refresh Windows 10