Selling Laptop, how to delete personal info

Hi, i've recently bought a new laptop and would like to sell my old one as it's in really good condition. I have just installed windows 10 but don't know how to erase my personal details, microsoft account and sign in details etc without changing these on my new laptop as well. Any help much appreciated.

 

Welcome to the laptop forums site

A Powerful and compact piece of software that allows you to destroy all data on hard disks, USB drives and floppy disks completely, just think how handy this could be if you are selling or just moving on a computer to someone else.

Just download the program and after installation choose a platform to store the program to
these include, a cd drive, usb stick, or a floppy disk.

Once installed onto the other drive I.E. a usb stick you can then run the program on
any netbook, computer or laptop.

Here's a link,

http://www.killdisk.com/