Hi everyone,
To answer your questions, there were a number of other steps I did in between, but in short I had a fairly new installation of Vista 64 Home Premium (OEM) with a 64 bit nvidia 8800 GT driver and Photoshop was slow. That being said, while OS WAS a new installation, I also had a ton of other stuff (both hardware and software) installed along with it. Tried flashing BIOS - no luck.
Then, through a turn of events, I ended up with a 32 bit Vista Home Premium with a 32 bit nvidia 8800 GT driver. Short of having that driver, Vista was clean as a whistle; I didn't even have the LAN and audio drivers on. Installed Photoshop - bang! Fast.
Then, since I had no clean Vista 64 Home Premium DVD, I found a download (must stress it's legal, or someone is going to get on my case - I know it). And while I was DLing it, I thought I'd go to play, and install Vista 64 Home Premium from the (dirty) OEM partition image. Sure it has bloatware, but I had time to kill and I was curious. It should be noted that this image had drivers for almost all hardware I have in the machine (no card reader). Installed Photoshop and it's running fast.
In all cases above I made sure OpenGL checkbox was on, and I used the same doc size every time with same settings to do the test.
In all cases I had 8GB of RAM loaded, so that's kosher too.
So, right now, it would seem that it's either a newer driver for a piece of hardware I have, or another piece of software.
My decision at this point is to take my downloaded Vista 64 Home Premium and load it using the key on a computer box. Crapware-free! Then create a hard drive image, install Photoshop and run the test. I expect it to run fine given the results so far.
Then I'll repeatedly cycle through creating a hard drive image, installing next driver or software and installing Photoshop to test it 'till it fails. I know it will, since I will eventually end up with the same configuration I had when it would fail every time.
When it fails, I'll note what piece of code made a difference, and load the very first image I created. Then I'll load the offending code and check if it craps out when that's the only thing installed before Photoshop.
And then I'm planning to continue up the ladder to test other software 'till I get everything on my machine. I want to make sure there aren't other things that might also make it slow.
Thanks for the word of support guys, you are the ones keeping me going.