QUOTE(thood @ April 4 2007, 07:26 PM) [snapback]110878[/snapback]
Um. There's a lot of things going on here, none of them fully baked. There's no such thing as 1200x600 ppi. 1200x600 just reflects the number of _fill in the blank_ you have. Pixels, inches, whatever.
If you're talking about a website, then you are resizing your images to 1200x600 pixels. Typically, the best way to do this is set your DPI to 72 (web standard) and then set the number of pixels to 1200x600. Make sure you set the measurement to pixels in photoshop when you're editing the 1200x600 number.
As to your scratch disks, I read through but didn't see anywhere you mention how much room you have on your main system drive. You have talked about your externals, but that's not relevant when it comes to your system getting bunched up because of virtual memory. How much free space do you have on c:, since that is where Windows defaults to build VM. Are you SURE the errors have to do with Photoshop's scratch disks, which are entirely separate from your system's?
Since you're talking c: d: I'm going to make the wild assumption you're on a PC and not a Mac (pity). Why did you partition your drive in the first place? It's rarely a good idea, and almost always a bad idea if you don't know what you're doing. Had you left it as one drive, there would be more room for scratch disks to play. Scratch disks are just what the computer uses when you run out of RAM. If you don't have a lot of RAM, the scratch disk (or virtual memory), can become quite large.
We need to know what kind of space you have on C: and likely, D:.
K