Accounts can only be created when placing a new order. To create an account, simply check the 'New Customer Create Account' option on the first page of checkout and enter a password. Once you have completed and paid for your first order, you will be able to login to your account here. Simply enter your username (the email used on the order) and password. You will also receive an email after placing your first order confirming your new account - you can now login at any time to place future orders this account.
Visit the Instrumentation Systems and Services Ltd website for more information on How to I register/create an account on your website?