Shopping for new pre-built PC that can run MS office and do medium duty as a D.A.W.

Hi Bob,
 A lot of pre-built (off the shelf) PC's come with a lot of bloatware and some of the internal components are consumer standards, but yet you can get a fairly useful machine as a DAW. 
I'm also on an old Vista 32 bit machine which can't keep up with the stuff I want to do in a DAW (limited amount of RAM (4 GB max for 32 bit) is one of the bigger problems) and I'm currently building a 64 bit machine. If you're going to record a lot of midi (soft synths), you'd really appreciate having more RAM (Win 7 or Win 8 x64).
 
What's your budget on this and will you be using 32 bit OS (XP Pro) or 64 bit OS?  

ampfixer has the right idea.  When I'm asked about buying a PC I always tell them "buy as much as your pocketbook can stand" or "buy overkill".
 
 

So, at the risk of sounding like an iconoclast, I would suggest that you buy what you need and not a lot more.
 
The reason is that for the user's purposes computer "power" is a poor measure of usability. I am typing this on a computer that has 8 gig of memory and a quad core processor, that I paid less than 300.00 to put together a couple of years ago. On the other side of the room is a computer that I paid about as much to make eight years ago running Windows 2000 with 1 gig of memory and a single core processor that would work just as well for this purpose. If you buy more than you need for your purposes, you deplete your bank account for a machine that uses most of its power as a space heater.
 
But what about the investment in future-proofing the computer? Again, it is not computer "power" that forces upgrades in most cases, but computer "features." The Windows 2000 machine has no SATA capability, no USB 3, a maximum of 1 gig of memory etc. Had I invested in the most powerful computer available back then, it would not have had much more in the way of "modern" features than the one I have. Upgrading that computer to have those features, would cost much more than buying new due to the necessary specialty board prices etc. Memory for that unit is now priced like an antique at about 12 times the cost per gig of DDR3.
 
The difficulty is in knowing what you need to do with the computer so you can buy/build the appropriate machine for current use, and save enough money so that when the next "essential" new feature comes along, you can upgrade. That is a difficult question, and I assume the reason you posted here. But the difficulty of answering the question should not mean that the answer is to buy as much "power" as you can afford.
 
I have not bought a prebuilt computer since my Intel 80286 machine, so I am not aware of what is available. I will say that, most pre-built computers have very limited expansion capability, and assemblers are not always forthcoming in their specifications about those limits.