Hi,
Once you have installed iClone4 EX and attempt to run it for the first time you will be prompted to login to your account. You should enter your username and password followed by Activate. You don't need a serial number.
If at this point you are getting an error message activating the software it may be that it is being blocked by your security software. You should ensure that the software is not being blocked in any way and try again.
Alternatively if this doesn't work you can create a new account for iClone4 EX, but you will have to use a different email address to the one of your current account.
If all else fails you can contact Reallusion Support who will help you with the activation process and some things to try to resolve this issue. Please use the link below to request assistance.
http://www.reallusion.com/CustomerSupport/User/QForm.aspx
Hope you get this resolved soon.
Peter
Forum Administrator
www.reallusion.com