user was running adobe acrobat prof 7.0 on a dell optiplex gx 270 on OS windows XP sp 2. The computer started having problems so we gave her different computer. Another dell optiplex gx 270 but on Windows xp sp 3. We un installed adobe prof 7.0 from her old computer. When I tried to install the software on her new computer it gave me 'invalide serial #" error msg. I called adobe and they verified that it was a valid serial number but they no longer support acrobat version 7. So I tried un installing windows service pack 3 to see if that would do trick. Same error msg. Can anyone help me?