Edit: March 8th 2018
I'll mark this as solved and add the solution up here for future reference. 
The problem was a new install of W7 64 bit which needed to run all updates as well as bringing the C++ library up to date. 
W7 is getting close to not working properly with some software. I even had trouble with Pace iLock. 
 
 
Start of original post: 
 
Well this is the first time this has ever happened. I have installed Sonar plenty of times in the past and it always worked. 
 
I bought a new SSD drive for my laptop and thought I'd start fresh. 
Installed W7 it's an older version so is SP 1  until it finishes updating which might be my issue. 
So first I just used the files from the old drive via a USB encloser and put everything Sonar back where it belongs ( was this a mistake?) 
I installed and ran Command center and then tried to install Platinum.
It almost finishes and then shows an error 
C\Program Files\Shared Utilities\CW120Auto.dll 
Unable to register the DLL RegSvr32Failed with exitcode 0x3. 
 
So I deleted everything all folders etc and tried again same error.
I tried downloading direct and ran that, same error. 
I just tried Home Studio. same error. 
So this is obviously my laptop is missing something?? 
Do I need to wait and update widows first, I usually do. 
 
 

It's a good idea to start by installing the C++ runtime library. This may or may not solve the problem, but it's worth doing anyway.

Actually the C++ 2013 library is on the system but corrupted when you get this message. I would recommend going here:
https://www.microsoft.com/en-us/download/details.aspx?id=40784
Download the package correct for your system and run the installer for bot 32 and 64 bit. It will probably prompt you for the repair option, so do that. Reboot and you should be able to run the SONAR installer from Command Center.
 
 

What emwhy sez! 

Thanks,, I ran the 176 W7 updates last night and installed SP 1- I thought there was a SP2 guess that was XP :) 
Just a few left to install and I was going to try Sonar again but I will follow your link first , might as well. 

not sure what 2013 has to do with it.
Download the newest VS C++here or here.
 
Platinum was coded using up to date VS c++. Unless your using a version from back in 2013 (like Sonar X2).
Download the newest one possible.
 
See this
https://www.cakewalk.com/Support/Knowledge-Base/2016000033/Unable-to-register-the-DLL-OCX-RegSvr32-failed-with-exit-code-0x3
 
Congrats on the SSD They are awesome.

not sure what 2013 has to do with it.
 
Only suggested that because that's what happened on my system last year. It was after a clean install but unlike the OP it was on Win 10, and it got messed up after I uninstalled something else and used a reg cleaner that maybe was too aggressive. It also affected some of my other programs from Native Instruments that suddenly were missing dll files and the fix lead me back to c++2013. 
 
Platinum was coded using up to date VS c++
 
Yes, but there are older elements in SPLAT incorporated from previous versions that rely on C++ 2013. That's why you see it install so many earlier versions of the various packages going back as far as C++ 2005. Just look in Control Panel/Programs and Features and you'll see a of them.
 
 
 

Well the good news is all this worked and I now have Sonar and am just updating everything else.
 
When I ran the CC library downloads they actually showed as "repairing" the originals so I'll put my money on that. 
But I guess in the past I always run Windows Updates over and over and then install my software. I think I just jumped the gun this time. 
 
The Laptop is WAYYYY faster already. Anybody still out there running standard drives you really need to get with the program. It used to taker a good minute to boot, now it's under 10 seconds to my password. Also just opening software in th pass took a while , now everything is just there. 
I have SSD drives on all 7 of my computer/Laptops now. Even my XP netbook was faster than this one. I think the original was a 5400 as well. 
 
I got this laptop from my Band mates Collage aged daughter after she killed it dead with a 100% full HD, a million torrents and who knows what else lurking. I traded her for a W7 Acer Netbook I also had given to me. She loves it as this one is real big and it has a keyboard issue with the right side is dead. I use a wireless keyboard.  It originally had W8 but Acer wanted $50 for the OS recovery disk. So W7 for free it is. 
Sjust to see how it ran I set it up using the original regular HD after I reformatted it. It worked out to be a real solid performer, but slow. So it will now be used a my remote studio. 
 
I will put a 120 GB SSD in the second drive bay to use for CWP files and audio storage. It will be plenty of room for how I will use it. 

Good news about the install, glad the CC fix seemed to work. That's exactly what happened to me about a year ago and it was maddening.
 
SSDs are a Godsend with older and even newer laptops. I have a Sony Vaio from 2009 and I put an SSD in it about 4 years ago. It runs fast, quiet, cooler, and boots up in no time. If it wasn't for the SSD I probably wouldn't have moved on from it.
 
 

I'm typing on a Sony Vaio ( VGN-NR460D ) as we speak. It was what I was using for remote recording until I scored the Acer. I put a 240 SSD drive in it a few years ago and used it for hours and hours recording 16 Tracks of audio in a band I was playing with at that time. Always works just fine. 
I now have it at work and use it for Downloading MIDI files and messing around in Home Studio. 
I also use it to rip and convert all our DVD's and CD's. 
It is my back up music player at gigs and runs a Power point show for my lyrics. 
My web page software also runs on this machine. 
The keyboard is getting unresponsive as letters go missing when you type. 
It boots in under 30 seconds even with W7. Solid little machine has needed no maintenance in years since I put that SSD drive in it.