1 – First open the Windows Store by clicking on the Store from Start Screen.
2 – Sign In to the windows Store by using your Microsoft Account.
3 – Swipe from the right side of the screen and select the Settings charm
4 – Click on the your Account under Settings.
5 – Now Under you PCs Click on Remove below to the PC you want to remove from your account.
6 – Now you are asked to Confirm, Click on Confirm.
Note – You won’t be able to use any of the apps you installed from the Windows Store on Removed PC.