The change to 512 of the I/O Buffer Size in the "Advanced" tab is a big jump from the default of 64. It does not need to be set the same as the latency buffers. Might want to try 256 first. Always use factors of 2 for this setting i.e. 16, 32, 64, 128, 256 or 512.

  Here are my observations from this weekend. I updated my Motu drivers. I installed DPC Latency Checker. I disabled the wireless card, modem, internal sound card, Windows Defender, Microsoft Security Essentials. I have the power management set up for performance and can't shut it off. I would prefer to not have Windows monitor my power management, but can't seem to disable it. I opened Windows Explorer, Sonar and DPC. I observed DPC for an hour while rehearsing. Nothing was running on the PC, although Sonar and Windows Explorer were open. I had yellow and red spikes. The red never reached the top but did happen. When recording, I had no dropouts or stuttering, also no pops and clicks. Something is running in the background and I can't find it or figure it out, but I have to in order to get the pc running clean. I also noticed that if I grabbed a window and moved it around the screen it would create a red spike that went all the way to the top. Please let my know what you think, thanks.

  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. Thanks man.

  Good question. When I run DPC checker without any recording or playback activity and it spikes...to me this is an indication something is running. I think the dropouts or white noise during playback may be the combination of me taxing the system at just the same time that it is spiking because of something else that I have not found yet and that combined with me taxing it during recording or playback may be all it needs to dropout or stutter or fail in some way. When this occurs I "of course" get the dreaded message from DPC telling me my system will not work when streaming audio or video. So, for me, trying to get rid of the spikes all together will give me a more stable system. This week or weekend I hope to start mixing some songs again so I will surely tax the system greatly and the problem might rear it's ugly head again. I will let you know.

  Thanks Scook. I have it ready to go when I get in the studio. Knowing my luck, I would need to purchase the professional version for $119.99 in order to solve any issues...lol. It looks promising though, thanks again.

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.

 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. 

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... 

  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.

  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.

  In the BIOS they let me enable or disable. I will disable. Before I do is there a way to check clockspeed? This way I can see what the idle speed and hi-speed was when it was enabled. I also can see what it will be locked into when I disable it. Running 800-2.9 is not better than a constant 2.1. According to what I read anyway. Let me know what you think. I also read about laptop cooling fans. I might pursue that as well. And in the control panel there are settings that may help. So I have all this printed out and ready to mess with when I have time tonight or tomorrow. Thanks

  You're right. I will just see if disabling the power management will satisfy LatencyMon. Trying it in five minutes.

  Oh by the way, I found nothing in "msconfig". Thanks

  I think you're right. Thanks

Yeah, threads now going on in Software and Computers. I did not realize the laptop was upgraded from it's original OS. If it were my call, I would restore the unit back to the factory config. That was what the machine was originally certified to run. But I am conservative that way. It may be incapable of running as a DAW but I would give it a chance using the factory installed OS and whatever minimal DAW tweaks were commonly applied at the time of the OS and DAW software.