If you need it just to upgrade then al you need is the serial number for that, if you want to use it you might be better off using it on the Xp box.
I think what the message might mean is you might have to install xp first then ai 8 then upgrade to windows 7 if that is possible.
You cannot "upgrade". You just buy a full new license. As for the rest - try what Wade suggested and install the baseline v8 first. sounds like you only have the 8.1 updater, not the full version. Even then it may not be possible to install software from the dark ages onto Win 7.
I was not aware that the OS does not have an upgrade version, my mistake.
I am going to guess that yu cannot install no matter how logical it might appear to be to the contrary.
So the best advice would be to move on.
However i think that Mylenium is correct what that message meant was you need the full version of 8 to install and not the upgrade. Then you can upgrade to 8.01 and then upgrade to a newer version.
This seems like a lot of trouble when you will be better of with version CS 5.
I am having that same problem, so far nothing that anyone has told me to try will work. I'm thinking that the only choice is to buy a copy of whatever the new version is now. Really sucks!!!! The Autoplay would not proceed to the Install part. So I opened the cd and tried using the setup.exe file. The error that I received at that point was -
This version is not compatible with the version of Windows you are running. Check your computer’s system information to see whether you need an x86(32bit) or x64(64 bit) version of the program, and then contact the software publisher.
Another wild goose chase???
Actually only the installer doesn't run in Windows 7. Cut the destination folder into which Illustrator was installed on your previous machine and paste it into 'Program Files (x86)'. You'll have to create your own shortcuts. Adobe probably doesn't endorse this method but it works fine.
Thanks for taking the time to answer. What you suggested not only did not work but now the photoshop program that I had installed & was functioning properly now won't work at all. Great Suggestion!