Well, activation for CS has been discontinued, so you are entitled to a non-activation copy of Photoshop CS2.
Download Acrobat 7 and CS2 products Be sure to use the serial number next to the download link, not your old one.
What do you mean by, "you can't download CS3"?
Have you tried this link? http://helpx.adobe.com/creative-suite/kb/cs3-product-downloads.htm
Gene
