Recently I purchased a new computer running Windows 7 Pro (64 bit) with 2 TB hard drive and 16 GB memory and faced the task of trying to install Photoshop 7, Illustrator 8, Acrobat 8 Pro, and Dreamweaver CS3 that I had used very satisfactorily on my old Windows XP SP 3, 2GB memory computer with less than 1 TB hard drive. I now have all of these running successfully on my new computer and thought I would share here my experience gleaned from a number of other forums after many hours. I had the most problem with Photoshop 7 which I will describe last. In all cases I had the original genuine installation disks. These are generally needed except for Illustrator 8.
Dreamweaver CS3 -- This installed easily in the Program Files (x86) folder & does not seem to require running in XP compatibility mode
Acrobat 8 Pro -- Same as Dreamweaver CS3
Illustrator 8 -- The installation disk would not work for Windows 7 Pro 64 bit. A solution I found in a Microsoft forum is simply to copy the Illustrator folder and contents into the ProgramData folder on the new computer along with the following dll files in the C\Windows folder of the old computer: icccodes.dll, kpcp32.dll, kpsys32.dll, pcdlib32.dll, pfpick.dll, sprof32.dll These go right into the Illustrator folder. This program needs to be run using XP compatibility mode (after copying preceding files go to Control Panel --> Programs --> Programs and Features --> Run programs made for previous versions of Windows -- follow directions there). It might be possible to copy into the Program Files (x86) folder too, but the ProgramData folder works. I have not actually used Illustrator after doing this, but since it started ok, I presume that there will be no problems.
Photoshop 7 -- My Photoshop 7 was an upgrade from Photoshop 5. The PS 5 installation disk would not run on Windows 7 & when I tried the PS 7 upgrade disk (autorun) I got the message that it could not find a previous version of PS & then shut down the installation. I tried the method used for Illustrator 8 above (suggested on yet another forum with an additional dll identified in another Windows folder), but I got the message "Could not complete your request because of missing or invalid personalization information". This evidently had to do with missing authentication serial code number in the registry. I found some discussion of this in forums but no workable fix in my case which involved an upgrade. Then I discovered inormation in another forum which explained that installation with the disks could be done by inserting the upgrade disk and running it from the setup.exe file instead of autorun. When you do this you are presented with the option of proving your previous version of PS by simply inserting the earlier version PS disk at this pint of the process. After doing this the installation with the upgrade disk proceeds fine. The PS 7 program can be installed in the Adobe folder within the Program Files (x86) folder. However, after doing this and trying to start PS 7 you get the following error (if your hard drive is 1 TB or greater in capacity): "Could not inititialize Photoshop because the scratch disk are full" After much reading I learned that this occurs because PS 7 apparently cannot recognize partitions (volumes) 1 TB or greater. What you need to do is set up an additional partition (volume) on your hard drive. This is easy to do. Go to Windows Help, search on "create partition", choose "Create and format a hard disk partition", and follow the directions. I decided to make a 50 GB partion I named "scratch". The system will assign a drive letter to it. To use the new partion to allow PS 7 to start you need to start PS 7 and immediately press the ALT and CTRL keys together. This will bring up a window where you tell PS 7 which drives to use for its scratch disk. You need to select the newly-created scratch disk(partition) in the first choice and leave the other choices as "None". After doing this you have one last issue. When you try to save any file in PS 7 you cannot save it directly anywhee on the C drive since that drive is 1 TB or greater. What I do is save it to the scratch drive and then later move it from there to where I want it on my C drive. I have seen it suggested to install the PS 7 program itself on the newly-created scratch drive, but I don't know if this would allow saving files to the C drive. When installed the way I have described it does not seem to require operating in the XP compatibility mode.
Hope this helps those of you who prefer working with the programs they are used to on Windows 7 Pro 64 bit.