Photoshop 4.0 on XP

I have Photoshop 4.0 on my computer. I have used it for quite some time with success. I recently upgraded, actually, I really made up a new, computer. I was using Windows 95. I now use XP. I installed a new hard drive, now shown as Cdrive, and I retained the old hard drive, now shown as D, E, and F drives. My Photoshop is were it always has been, i.e., it was on Cdrive in the old configuration and it is now on D drive. When I launch Photoshop I get a window that says, "Unable to load PSUT9532.DLL.Photoshop will not be able to support 16-bit plug ins.Continue launching?" I can access it with no problem, and it seems to function properly, but the display is of a very low resolution and there are messages that pop up with questions about different bit rates, 8, 16, and 32. I postulate that I need some sort of plug in to conform with XP? I’d pose this question to Adobe, in hopes of buying the plug in and making this work. But, as I see their website, it would cost me $150 just to ask what can be done. Not too encouraging. FWIW, I am a regular guy who likes to, from time to time, modify his images. Buying a new copy of Photoshop is pretty much out of the question. I have several image programs but there are certain things, things that only Photoshop will do, that I find very useful. I’d be very happy if my Photoshop would just work in the same manner it always has in the past.

Thanks

Tom