I just built a whole new DAW from the ground up. My old DAW is still working as a back up. My routine over the years is to never nuke the old system until the new one is working properly.
If I re build the same box, I put the original OS drive to one side and use a new one. Never nuke your hard drives if you can afford a new one. Just put it aside, or put it back in as a Data drive.
I ran windows updates for a day and a half.. It takes that long it seems. While that was happening I installed all the updated drivers for EVERYTHING. MOBO, SSD drive, Interface, My Coffee maker, my mouse.
I always install my Audio interface, Roland A49 and Yamaha DTX drums drivers before loading Sonar. That way Sonar discovers them and is happy. Sonar does not like to wake up in bed with a Realtech or a Soundmax card.
It is recommended (somewhere around here) that if you desire older plug ins the easiest way is to just install the older versions in sequence form oldest to newest. Because of 64 bit, I see no reason to go beyond 8.5.
So I installed Sonar 8.5 Producer bare bones first, then X3 and the e patch. Within a few weeks of this the new version has came out so I have now installed Professional now too.
Sonar takes up very little room, it's the samples and extra stuff that are hogs, but you can move that stuff after the fact or during install.
I'm using a 128 Gig SSD for the OS. Only programs are installed there. It is sitting at 25% right now and I have a lot of Software on it. Boy is it fast to boot and open apps...But that's also Windows 8.1. My Windows 7 DAW takes forever to boot!