How to partially format a hard drive?

[Gdn8Melbourne3]

I just installed Windows 8 on my computer. I placed the files I wanted to keep on an external hard drive prior to the installation, that is fine. However, I though that the process would format the computer's hard drive, which it did not.

Is it possible to format my hard drive in order to keep only what is related to Windows 8?
If not, can I format the whole thing and re-use the same Windows 8 key?

Thanks for your help

 

[eidairaman1]

Is this an upgrade edition or did you install this ontop of another windows version?

 

[P4-630]

https://support.microsoft.com/en-us/help/17085/windows-8-restore-refresh-reset-pc

 

[EarthDog]

You cant format a drive and expect data to be on it...unless it was partitioned. But in that case, you wouldnt be accomplishing your goal either.

Its a full format and reinstall. Of course you can use the same windows license with the same hardware.