The problem you are having is you are entering an incorrect Registration Code.
We just released Microstudio 2.604 yesterday. Find your email with your Registration Code and download link, click the link again to get the new microstudio2604setup.exe file to your computer. Then, run this to install it instead of your 2.517 you are trying to install.
Microstudio 2.604 shows you if there is a problem so you will know exactlly what to do different to complete registering. 
For those who might see this, we will add this new feature in all our software products as fast as we can. This will prevent the frustration of doing the same thing over and over.
Now... you will see what is wrong and what to do to fix it... the first time your registration attempt fails. 
We have been working hard all year on updating our web site and out Installation program to provide this live feedback. This should make it easy for everyone to quickly register.