GIGABYTE GA-970A-UD3P
AMD FX-6300 Vishera 6-Core 3.5GHz
G.SKILL Ripjaws X Series 16GB
 
All for $275 BTW this is as far as I will go in spending on an upgrade for this machine.

This is not really meant to be a main DAW. I have a Terratec EWX running solid with Vista beta drivers and a Guitar Port.

My biggest hurdle is I have a W7 Pro OEM license when it will come to activation. I don't remember how this will go with MS.
I know there is a program called Remove WAT that eliminates this hassle. That would be step 2 if dealing with MS fails, Step 3 is reverting back to W7 Home.

  Have any of you had experiences dealing with MS with an OEM W7 license after making such changes.
 
The bold is the response I'm looking for.

I purchased an OEM license back in 2007 for a self built system.  A few years later after a MB failure, I purchased a new MB, processor and memory.  I did not change the O/S disk and I had no trouble with my windows license.
 
I would caution you on the use of a Gigabyte motherboard though.  I had a bios issue with the southbridge chips set that made processing audio difficult (I had to get a special bios from gigabyte, it was a beta and I don't know if they ever released it) and then that mother board failed 3 or 4 years later.  I think others have noted issues with gigabyte as well.
 
I would recommend an ASUS and have seen others recommend that brand, too.

As long as the copy of Windows is only installed/running on a single machine, you're not violating the license.
You're allowed to upgrade the single machine.

With W 8 when I re built, it just asked if I wanted to activate and took me to the account web site. I had to answer a few questions and enter the original key. The important question was it will ask "how many computers has this licence been installed on" Correct answer 0. 

Jim Roseberry
As long as the copy of Windows is only installed/running on a single machine, you're not violating the license.
You're allowed to upgrade the single machine.

 I thought I would be one of those activations calling MS.  I typed the product key and was activated online. I've had to call a couple of times with a regular license.  BTW I don't know if the licensing is different but it was a Windows Any Time Upgrade.

dwardzala
I purchased an OEM license back in 2007 for a self built system.  A few years later after a MB failure, I purchased a new MB, processor and memory.  I did not change the O/S disk and I had no trouble with my windows license.
 
I would caution you on the use of a Gigabyte motherboard though.  I had a bios issue with the southbridge chips set that made processing audio difficult (I had to get a special bios from gigabyte, it was a beta and I don't know if they ever released it) and then that mother board failed 3 or 4 years later.  I think others have noted issues with gigabyte as well.
 
I would recommend an ASUS and have seen others recommend that brand, too.

I still have a Gigabyte socket A in storage plus many Asus boards.  Asus is usually my first choice.  Too bad Intel got out of consumer boards.  Intel was top notch in RMA. Asus is one of the worst in RMAs. Never had to RMA an ASUS.