It won't "upgrade" per se. Like others, I would say to put your current drive in an enclosure, then plug it into your new system (or your newly upgraded system) AFTER you've booted up the operating system, or it may not know which drive to find its OS from!
Once you have, then your old files are all there for you to be able to access from your new installation. You will need to reinstall all of your programs to the new drive, but all your data, files and documents will still be on the old system, including old SONAR files. Cleanup may take you quite a while, though, as I just did this same thing not long ago, 'upgrading" from XP64 to Win7 64. Wasn't fun, but it's all done, finally...good luck!!