As others have said you will likely in-register Windows.  Obviously you have to do a fresh complete install of Windows - you shouldn't restore from backup or disk image.  Plan on reinstalling ALL your software.  I won't say its impossible to do a major system upgrade from AMD to intel and restore your windows install, but I would recommend a complete fresh Windows install on a formatted disk. 
 
With regards to Cakewalk et al, you should uninstall Cakewalk before downing your current system.  This "frees" you Cakewalk license and allows you to reinstall without issues.  I've uninstalled and reinstalled Cakewalk about 6 times for different reasons (used on laptop, rebuilt laptop, transferred to desktop, got new desktop, etc). 
 
Good luck with your upgrade.  Let us know how it comes out and if we can help further.

There's no reason to uninstal Sonar. As long as you have your 2 numbers you are good to go. 
My DAW is not even on the internet, I just installed X3 studio and all I needed was those 2 numbers on hand. There is no communication needed with the mother ship. We should all be thankful they make it this easy. 
 
And I will also agree with those who are recommending you will need to be doing a fresh install of Windows to a formatted drive. 
But what is important is if you have a OME version of windows then I'm not sure you can use it as it is tied to the original computer and MoBo. 
But if you have a full disk version of Windows the serial number can be used in a new computer. 
It may take a phone call to Mircosoft that's all. I've done that before. They are actually very helpful. It was Malaysia. 

This is why you never upgrade or change anything unless your back is to the wall and you just absolutely have to because of (1) PERFORMANCE problems (as in Sonar no work) or hardware failure ...   :(

Ooooh that smell
Can't you smell that smell
Ooooh that smell
The smell of death surrounds you
 
Not only will you have to deal with driver issues, reauth's, and redoing all the zillion tweaks you've done over the years/months ... the WORST experience is when you open up previous projects and they are all screwed up, because you forgot to save this or that exacto-mondo, because paths have changed and something can't find something quire right, or other crap.  I absolutely HATE upgrading my DAW.   I just want to turn everything on, kick back, chill out, and everything technical works the way it's supposed to work!!  
 
Did you try to overclock.  The 945 easily overclocks to 3600.  Know how?