X1 Producer Expanded without any problems (or very rare problems). My setup at the moment is driving me round the twist with constant drop outs and blue screens that are becoming more common. 
My CPU is 2188, which I realize is extremely low for running a program like Sonar. So what would be the best option, keeping in mind I am trying to keep costs to a bear minimum?

Never heard of a 2188 CPU.... what is that? Is it Intel or AMD? Dual or Quad Core?  

Are you upgrading your whole system or just the CPU? I'm quite happy with my i7 2600k but you should be able to get away with the i5. I think you're generally gonna want to be looking at something around the 3.0 Ghrtz range to get the most out of your system. Check out Tom's Hardware online (just google it). They have a ton of comparison charts for stuff like this. Also I'd imagine Gearslutz would have similar charts but more focused on DAW systems. Cheers.

Also you could squeeze a bit more power out of your current system by optimizing it for audio production if you haven't already. Sweetwater has a good guide for this (it is the one that was recommended to me by Cake). Focusrite has one as do many other sites. In fact I think Craig Anderton has a guide up over at SOS as well. Again just google them. They should pop right up.

Oh sorry, 2188 is the CPU benchmark but it is a Pentium Dual Core E6700.

Well I was only planning on upgrading the CPU, but I'm not sure if I have to upgrade my motherboard or not....  do certain CPU models need more powerful motherboards?


EDIT: Ok Beepster, I'll check that out. cheers

To quote the site:

SONAR X1 Producer System Requirements

The following are the minimum recommended system requirements for SONAR X1 Producer.
 

• Windows XP Service Pack 3 (32-bit)/Vista Service Pack 2 (32- or 64-bit)/Windows 7 (32- or 64-bit)*
• Intel Core 2 Duo E8200 2.67 GHz/AMD Phenom Quad Core 9750 2.4 Ghz
• 2 GB RAM
• 1280x800 minimum screen resolution
• 4.5GB for minimal installation, 15GB for complete installation
• SONAR on DVD: DVD-ROM, DVD+/-R or DVD+/-RW Drive
• SONAR download: Broadband or better internet connection for download
• Cakewalk Publisher requires available web server space with FTP access

* Windows XP Media Center and Windows XP 64-bit are not officially supported. 

I seriously doubt your processor alone is your issue though, being that you're experiencing BSOD's.

What's the rest of this system's configuration...ie your memory, video card, dedicated audio card used or on-board soundcard/chip?

It's likely you will have to upgrade the motherboard which sometimes leads to having to upgrade everything else too. Like if your drives are IDE you'd have to swap them out for SATAs or if your power supply can't provide enough juice for the new set... stuff like that. I'm not familiar with that chip nor what motherboard standard it would use but definitely check out Tom's Hardware to see what is available for your motherboard. That should be your starting point. Figure out what the board is then look at all the available CPUs it will take. Then look at the most powerful one. If it falls into the acceptable requirement range for X1 then there is your answer. Also system optimization may very well clear up all of your problems. Simple things you can do right now are turn off Windows Power Management and turn off your anti virus when you aren't online. Also if you haven't maxed out the RAM capacity of your motherboard getting some more RAM couldn't hurt either. Good luck.

Oh and what audio interface are you using? Sometimes that's the simplest fix.

All of my computers specs meet the minimum system requirements which I thought was odd..
Well I'm using the E-MU 0204, which I wouldn't have thought would cause any problems.  How can you find out the amount of RAM your motherboard can take? I have 3GB at the moment, and it is the motherboard that came with the computer so I assumed it is not powerful enough to hold any more. 

What Operatng System are you running?