Well, if you don't plan on bumping up your RAM, 64bit will do nothing for you. Yes, 64bit OS can address more RAM and even 32bit apps behave better, but 64 bit OSs also require more RAM to begin with because they are "fatter". On your current system, any potential gains would probably be eaten up by your OS generally feeling slower and taking its share of memory away from programs. If you do go 64bit without changing anything on your system, you can use Win 7 Home. From your description, your computer is an older model and won't need or satisfyingly run any stuff in Professional or Premium, anyway. Just be wary of potential driver issues and what have you...
I definitely want to increase RAM also. I have 2 memory card slots so I was thinking of going up to an 8GB card and leave other space open to potentially add another 8 later. My computer is not neccessarily old, I had it built 3 years ago but had to have a new mother board put in last year. I kept Windows XP because I liked it. I would love a new computer but it is not in my budget right now. Do you think I should go to Windows 7 and put in the 8 GB? If so what, edition is best or would you suggest something ese entirely? The tech at Micro Center said something about having to disconnect my video card, which is NVIDIA 7300 GS, before installing the new Windows and then see if the program ran better. He said I may not even need the NVIDIA video card. I am a photographer and am always working on large photo files, adding effects and actions. I have worked a little inside my tower, is this something that will be easy enough for me to do myself?
I am a photographer and sometimes shoot in RAW or large JPEG. Straight from the camera the jpegs are 60.2M and 78x52 inches. Once I edit and apply effects, photoshop will not allow me to save anything above an 8x10. Message reads - cannot save file, there is not enough memory (RAM) Also when I am opening a graphics layer or overlay, it will say - Could not complete the open command because there is not enough memory (RAM).
My settings in Performance Dialog are -
I also get a message when opening that says the Graphics Processor is not recgonized...... deselect use graphics processor to improve performance. I still get the message whether i have that box checked or not.
If your computer isn't particularly old and apparently has 64 bit capability, I would definitely look into going with an all-new 64 bit OS.
There are those of us running Photoshop in Windows 7 x64 with great success.
And RAM is incredibly cheap right now. I'd suggest going up to 16 GB if you can, even if it means replacing all the RAM you currently have.
Something to keep in mind is that Windows 8 is going to be released this Fall, and it will be be priced at $39.95 for an upgrade (yes, even an upgrade to XP).
However, if you liked XP over its successors, you may dislike Windows 8 even more. I've already written a book on how to tweak and augment Windows 8 to be a work-oriented system because out of the box it's not anything like its predecessors - the desktop isn't where you start, and when you do find your way to it to run what Microsoft considers "legacy" Win32 code there's not even a Start button.
If you really want to start talking about pushing performance into the stratosphere, I can suggest some ways to use SSD that can help you do so, though that's still costly.