Windows 10: I bought my laptop that came with genuine Windows 10 OS. I now want to reformat my laptop...

I bought my laptop that came with genuine Windows 10 OS. I now want to reformat my laptop and I'm wondering how I can reinstall the genuine Windows 10 since I don't have the authentication key.

:)

 

Installing English version of Windows 7 on a laptop that came with Japanese version

Last time i made the mistake of using the restoration software that came with a laptop, it reformatted the entire hard drive, except the restoration part, and basically returned it to the same state as when the laptop was bought. The problem was that i had split up the original C: partition into two partitions, one for OS and a second one for storage and was thinking that it will only reformat the C: partition.

 

Reformatting Laptop

I'm planning to reformat my laptop and in the Activation tab it says that i have a digital license activated and linked to a microsoft account. My question is if i reformat my laptop would it wipe the Windows 10? I purchased this laptop not knowing if
windows 10 is the default OS or it was installed by the store.

The main reason why i'm reformatting my laptop is because of USB mass storage driver is faulty and no update or installation is fixing it, i even contacted microsoft agents and ASUS agents (my laptop is ASUS x507ubr) and tried all the things they said from
system recovery upto downloading manually of specific drivers. Finally i decided to take it into the local ASUS store so that they could take a look and they said the only way is reformatting a laptop. They suggested that if i know how to do it i should do
it so i wont take extra charges. Hence my question above.

 

Installing English version of Windows 7 on a laptop that came with Japanese version

Well, this lappy came with two partitions. C is 80GB (I won't use more than 30GB) and 204GB for D partition. Restore partition is before C drive and it's 20GB.