I had an inexpensive sound card in there with digital S/PDIF Optical in and out. That card was giving me other troubles, so I just put a Creative Labs Z SE card in there. There is no change in the stuttering.
I have tried MME, ASIO and WAS and all three exhibit the same issue. I'm going to assume that it is not the audio card, although I won't rule it out completely.
I have an Edirol USB audio interface I can use. Not a good one.
I grabbed these from 3 posts of yours on this thread. Sounds like you have at least 2 if not 3 cards. I don't know the model numbers (and drivers they use) of any of them because you didn't reveal that info. That could be helpful. You said you replaced an inexpensive card with a creative card. You might have simply replaced one card that can't handle it with another card that can't handle it and doing that didn't resolve the problem. Kinda like replacing a bad spark plug with another bad spark plug in an engine. It's still not going to work right.
So... years ago, I was pretty active in the Cakewalk forums and helped quite a few new folks get started. If there's one fact that I know.... You gotta have a GOOD, SOLID, NATIVE ASIO running, interface. One of the big things we came up against was Sound blasters, Lab something or other, and Creative cards (oh yeah and UNO midi cables and lets not forget USB condenser mics... but I digress) and people trying to use them and having issues. Trying to run them with ASIO (didn't work cause the card couldn't handle it) or MME, or ASIO4ALL, again, a fail.... I know you say your CW works well and has no issues. you have 2 computers and this issue is with the desktop machine. the laptop is working.
If there's any way you can get your hands on something like a Focusrite Scarlett or something from Presonus.... load ASIO and try that, I'd be curious to know how that works. Borrow one from a friend locally if that's possible. Having a known good interface and solid ASIO drivers will eliminate that as the cause. I know what it's like trying to run a DAW machine with old gear that barely plays mp3 files.... Been there.
What has me puzzled about this as I kept skimming your thread was you mentioned that after you hit PLAYBACK it starts and then randomly starts regenerating the tracks in differing places in the song and that's when the stuttering starts. That right there is really bizarre. That makes me think its a corrupted file in BB. But then again.... if you are running on your laptop and it runs fine and it's the same exact BB and build.... it's gotta be something in the machine itself or the interface/driver. Gotta be.
It's difficult enough to troubleshoot a single problem but if you have two things messing you up that is exponentially harder to resolve. But I think it's just one thing and when you find it you'll be running smooth.
Anyway.... good luck. I'm sure you will eventually get it sorted out. When you do can you please let us know what was causing this? Thanks.