You do have to get rid of the spikes. And with some laptops this is just not possible. I have seen this my self. There are processes that cannot be easily disabled and they are most often burned into the BIOS. Laptops are just like that. 

You can run the DPCLAT meter while messing around, On one laptop I had the minute I turned on my interface the whole reading jumped from 300ms to 500ms. I posted pictures here and asked a few questions. It only does it on that one laptop. 

But if there are red spikes the audio engine will possibly be interrupted. Not always, but possibly. I would record a test tone while observing the meter. 

TremoJem

I wish I could, but not without upgrading Sonar too. I mean really...I have to go to a complete upgrade to Sonar to use Windows 7 or 8. It sucks. 

If you're assuming that Sonar 7PE doesn't work on a Windows 7 platform, you'd be wrong.

  Thanks Cactus Music, I will set up to record using a test tone with a midi input, I think that should be fairly easy to do, although I have never done this. Kev999 WHAT?! I did not know that I could upgrade to Win7. I called Cakewalk when it first released and they said no way! What do I stand to gain by upgrading to Win7 Ultimate? Please explain, thanks.

 Use an audio tone from a synth that's nice and even. A smooth wave, That way any glitches will be obvious. MIDI data would see if a soft synth is cutting out which is possibly useful info too. . 

I have Sonar 7 ( 32 bit)  producer running on my Windows 7 64 bit computer. I didn't use it much, only to finish off my old 32 bit projects. But it ran better than ever. I used to have the audio engine stopping all the time when ever I tried to use some soft synths. 
All my troubles went away when I switched to W7. For me it was like night and day. 

http://www.meldaproductio...?id=MFreeEffectsBundle contains MOscillator (a tone generator) and several other free tools you might find handy.

Upgrade to Windows 7 ASAP. Before they stop offering it. 
I used to have an upgrade offer for W7 for my Asus Netbook, now they are only offering W8. So I regret waiting too long. I don't have any interest in W8 right now. 

My daughter has a laptop running Vista and it has been nothing but a terrible experience for her/ me. It takes over a minute just to load drivers for something simple like a USB flash drive. 

Example: 
We bought a Canon wireless printer. 

XP computers= Had to use the CD which installs bloatware with the drivers, no choice. 12 minutes or more to install , another 10 minutes to delete bloatware. 

The daughters Vista 32 bit = CD drive would not open the software. Took 10 minutes to straighten that out with the administrator thing. 
Then it seem to take 20 min. to install the same software. Then It took forever to unistall bloatware....everything you do takes longer.
  
W7 computers= recognized the printer and up and working in less than a minute,, no need for the supplied software disk. 

That's going to add up to a lot of time saved as life goes on. Look at how much time you just wasted, probably because of Vista too... 

TremoJem

Kev999 WHAT?! I did not know that I could upgrade to Win7. I called Cakewalk when it first released and they said no way! What do I stand to gain by upgrading to Win7 Ultimate? Please explain, thanks.

Surprisingly, Sonar 7PE-32 worked without issues as soon as I installed it on W7-64.  Sonar 7PE-64 had some issues but I solved them eventually.  Some of the plugins were problematic, but that was not due to Sonar.

  Thanks for all the great tips from everyone. I ran LatencyMon. Here are the results. "Your system appears to be having trouble handling real-time audio and other tasks. You are likely to experience buffer underruns appearing as drop outs, clicks or pops. One or more DPC routines that belong to a driver running in your system appear to be executing for too long. One problem may be related to power management, disable CPU throttling settings in Control Panel and BIOS setup. Check for BIOS updates." I went into the BIOS and found nothing on power management. And can't disable it while booted up. The only thing in the BIOS for CPU management was some OS crap that manages the performance of the CPU..."step" something or other. I did an update with MS so if there was any BIOS update I guess that would have been done...I don't know. Oh, and I found nothing in the Control Panel to manage CPU throttling. Help, if you can. I will try to fix this first, then I will have to upgrade to Win7, but I will call Cakewalk first to see what they say...then again I don't believe they support my release anymore, but I just want to make sure I can go back to where I was or am now, as I can't afford to upgrade Sonar too. I remember them telling me when I bought the release I could only install it once or on one machine. As long as I can re-install should Win7 not work, I don't mind trying Win7. Damn computers. Give me 1/2" analogue tape back...yikes.

That is progress...of a sort. BIOS updates would not come from Microsoft, you need to go to the hardware vendor for that. I believe the "'step' something" is the power management that LatencyMon is pointing out as the problem. Sounds like Intel Speedstep. There is quite a bit on the internet about what it does and how to turn it on/off.

  Yes, I think you have it right..."SpeedStep". It says that if I disable it that it is in the "low performance" mode or something. If I enable it then it is in the "hi-performance" mode, so I did nothing. I will google it and get a better understanding. Sounds like Intel made the Bios, so I will google that to figure out if any updates are available.