Installation and activation problem

Hello
bought SR in december 2012 and after i received my serial number it worked very well, with 3ds max design 2012, vray advanced 2.0 and win 64 pro. One week ago i changed my OS to win 7 pro, than when i tried to install SR, the first difference was to have to give it the folder of the installation. I gave it plugin folder of 3dsmax design like destination folder, once installed when i launched 3dsmax
it asked me the serial with the same request code of the firs time i installed (SR099_028128349), so i wrote mY s n 8950124 and appeared the following message_ MAX SCRIPT _"Unable to write the request code file. Please relaunch your 3dsmax with Admin rights for activation process", when i pushed ok 3ds max geve me another message _MAX SCRIPT_ "Somethingh bad happends....Can't find Preset file. Please reinstall Solid Rocks". I tried to reinstall many times, but with no success.
but i am the only user like Admin for this computer and so i install it like Admin.
Can you help me?
Many thanks
Stefano