Community Tip - You can change your system assigned username to something more personal in your community settings. X
Did you run the setup as administrator or at least with sufficent rifgts to write the registry?
I installed it before but now I formtted my laptop and trying to install it with the same steps before,I did'nt do any thing special from the time before formatting.
I don't know is it from the antivirus maybe it prevent it from the thing that you say about.
How can I give it the rights you mean?
Maybe right-click and "run as administrator".
Which OS?