Windows 10: How to clean re-install Windows 10 Single Language on my Lenovo Laptop

I have Lenovo G50 70 with Windows 10 Single Language on Partition C (Upgraded from Windows 8.1). I want to re-install Windows 10 SL as my Laptop has become very slow. I have Windows 10 SL on DVD as well as on USB Pendrive which I had downloaded as ISO from Windows 10 website. Now I would like to know - how to re-install the same which does not cause me any problem as far as activation is concerned and it should be a clean re-install. Please advise me step by step. At the time of reinstallation - will I have to opt for " formatting my C drive".
My internal hard disk is password protected which I could not remove. I had tried many times by going into the bios but the option to select Admin Password and Harddisk Password could not be done. The up and down keys just do not navigate to these options. Any help in this regard is most welcome.
Therefore will it cause any problem at the the time re-installation of Windows 10 Single Language.?
Please help me re-install my Windows 10 SL.
Thanks in advance
aria

:)

 

ACTIVATION PROBLEM WITH WINDOWS 10

I have Lenovo laptop with pre installed windows 8 single language edition, which was subsequently upgraded to 8.1. I had to re-install windows due to unstable performance. Windows 8.1 could not be refreshed as "Drive on which windows is installed is locked"
error came in. Then I downloaded the win 10 "Media creation tool" and performed clean install.

Now windows 10 is not getting registered. Please suggest what can I do. I know the win key from BIOS/UEFI but win 10 is not accepting it.

 

Windows 8.1 Core Single language to Win 10 Home different language installation

Hello,

I upgraded my Lenovo with 8.1 Core Single language /english/ to Win 10, activation was OK. After that I made a clean install of Win 10 Home /slovak language/. Now I cannot activate Windows 10 for almost 3 days. Is it due to the change of language, the fact
that slovak language is not available as "single language version" or are the servers busy? Should I reinstall an english single language version of Win 10 Home or just wait some time for the activation?

 

If the operating was upgraded during the free period you should have a digital license.

Many problems with the operating system can be fixed by performing an in place upgrade repair.

If there are registry problems then you can consider a clean install.

Another option to consider is using Macrium to make a backup image.

There may be others that can guide you on the password problems.

Clean Install Windows 10 Installation Upgrade Tutorials

Repair Install Windows 10 with an In-place Upgrade Installation Upgrade Tutorials

Backup and Restore with Macrium Reflect Backup Restore Tutorials

 

Thanks for prompt response. I will go through these links and choose an option best suitable for me.