Adobe CS3 not working on Windows 7

I recently got a new laptop with Windows 7 64-bit Home Edition. I had Adobe CS3 installed on my computer, and know that Photoshop and Illustrator seemed to work fine. Then, in order to be able to use rare special programs that were only compatible with Windows XP, I upgraded to Windows 7 Enterprise (also 64-bit). Windows 7 Enterprise supposedly has an XP compatibility mode that should allow older programs to be installed. I did not reformat my hard drive when I did this (the first time at least), I just reinstalled the operating system. I had to reinstall all my programs though, including Adobe CS3. When installing CS3 on my new Windows 7, there was an error message about some weird file missing (I think it was called pdf.dII or something, apparently a common error when installing CS3 on Windows 7. I just clicked ok and it said it installed successfully. However, whenever I tried to close a CS3 program such as Photoshop, the program would freeze and I have to force it to close. I tried reinstalling CS3 and installing CS3 without Adobe Reader 8 Professional (because supposedly that weird pdf.dii file was needed specifically for Adobe Reader 8 Prof), and it still had this problem. One problem I also found frustrating was that I could not completely uninstall CS3. When I went to my "programs and features" from the control panel, it would still have the adobe CS3 icon sitting there, but would indicate it had been uninstalled. Also, I had set my default PDF reader to Adobe Reader 9, which I had downloaded from online. Even though I had supposedly uninstalled CS3, supposedly hadn't even installed Adobe Reader 8 on my computer the second time I installed CS3, and set the default PDF reader to Adobe Reader 9 (not 8, which comes with CS3), somehow whenever I tried to open a PDF file my comp would try to open it with Adobe Reader 8, then get confused and freeze everything for a while. It seemed as though somehow my computer didn't know Adobe Reader 8 was uninstalled, and there was some program scrap somewhere I wanted to get rid of. I tried to delete any remaining Adobe CS3 files, but since I did not reformat my hard drive before reinstalling my operating system, I had random peices of program files from my old operating system laying around in my old Windows 7 user. I found some adobe associated files in some very unexpected places on my computer, and truly do not know how they got there.

I didn't like the idea of my computer having scraps of program files laying around that were associated with my old windows 7, and thought they might interfere with programs like CS3 somehow, so I reformatted my hard drive and reinstalled windows 7 enterprise again.

NOW, Adobe CS3 does not work still. This time, I can't even open any of the programs to begin with. When I open Photoshop, it will try to open for an hour until I finally tell it to give up. Strangely though, it never asked for the activation code this time. I have a code, and it just simply never even prompted me to type it in. I don't know how to get to a spot where I could type in this code, and don't even know if this is my problem.

Does ANYONE have any idea what could be going on here? Thanks so much for any advice.