help with harddrives

[GoldenGamerUK]

if i have a shop bought pc with no custom parts, and the os tied to the motherboard meaning that i cant use the harddrive with the os attached to it in a completley new system if i wanted to, how would i go about taking the OEM os off of the harddrive meaning that the harddrive is basically a Normal harddrive with nothing on it, and installing the os on the harddrive when the harddrive is placed in a completley new machine? all help is appreciated!

 

[markwp]

Buy a copy of windows (7 or 8), put the hdd in your new rig, boot to the dvd/usb of the new windows and choose new install. Windows will overwrite and reformat the drive for you and you're good to go.