Make sure the name you're putting in is the same as what you registered. Iirc it's your email address, but i'd check the message you received from piriform (the register button you pressed is the correct one).
Hi Andy007 , all i can tell you is that CCleaner has a free program and a Pro Edition which you pay a yearly cost , but the free edition is , of course , free.. If you purchased the Pro Edition they send you a license key of 20 characters will alpha and numbers. You have to type in that license key into the 5 boxes and then you can use the Pro Edition if you indeed purchased it. Hope this helps. Don Barajas