Hello, this is my first time posting here, I'll thank you guys in advance for any assistance.
 
My main desktop computer has Sonar Pro, running through a Scarlet 2i2.  I've been trying to record an entire song sans vocals on my desktop, (beat, guitar, and bass track).  I also have Sonar Pro on my laptop. The idea was to record vocals in the truck with a USB mic on the lap top.
When I save the song, or all instrument tracks to a flash drive, I transfer them to the laptop.  When I try to sing vocals on to the laptop, I save the vocal track, then take the track back home to the desktop.  When I do this, the timing is off.  As if the vocal cadence is at a different tempo than the original song. (The laptop recorded vocals does not keep up with the desktop recorded track) I hope I explained that right.
 
I have an older Toshiba laptop, not sure what kind of sound card it has.  Is there a better way to do this? Thanks
 
PS. If I need to move this in to a certain thread or section, let me know thanks.

When you say you transfer to the laptop what are your steps? 
 

From laptop, I export only the vocal track on to a flash drive.  I take the flash drive home, save track to desktop. (or wherever) I create an additional audio track in the original song, then import audio.

That's because USB mikes have bad audio drivers and the results are track will be out of sync. 
You might try using ASIO4all and see if that keeps it in sync. Below shows what I'm talking about, This is a loopback test which shows how different audio modes behave. You record the original audio back to tha new audio track and you can see which mode calculates the RTL correctly.  Only ASIO keeps timing correct. ASIO4all basically makes Sonar think it's using ASIO mode. 

Make sure your audio timing and MIDI timing settings are the same between your laptop and your desktop.  I've marked the most important in green here:
 



 
If using the same project files, obviously you'd have the same tempo set.  But latency will always be different across different hardware configurations, especially a laptop.  If your audio latency is different, adjust the sliders so that the bottom number "Effective latency" is the same.
 
Verify the settings I have marked in green here are all the same.  This will ensure the same output from both computers.  Run your Wave Profiler if you think whats displayed there is innacurate.

OK. I believe it was on ASIO already.  Are there other options? Is there a such thing as an interface that doesn't require power that I can plug an XLR mic in to? Thanks

The Scarlet 2i2 is USB bus powered and you can plug a microphone in using an XLR cable

Your 2i2 is one of the few that will run off USB power, you must realize that as it does not have a wall wart. 
 
Loopyd post is not correct, it's has no bearing on using different computers what the these settings are,  You problem comes from the use of a USB mike.  I use 3 different interfaces and 3 different computers and each is ,, well, different. The only setting that matters is the clock rate needs to be the same.  If you look at loopyd screen shoot youl see the reported latency is 10ms same as my screen shots for all but the ASIO4all mode. That is what you get with on board audio and most of the driver modes and it is basically reporting wrong so therefore the offset is out. In my case the real offset was 11.6 
So therefore yes staying with ASIO will be best and if you can using the same interface makes Sonar very happy. . 

I'm getting more and more frustrated with the latency of USB busses, even on good hardware.

Loopyd are you using an interface or on board like your screen shots show? 
If your using on board you will need to use Asio4all or you'll always have issues. ASIO drivers are all that work correctly with Sonar. WASPASI exclusive is second best but if you look at my screen shot you'll see it failed the loopback test for overdubs.