Windows XP Service Pack 2 misreports as Win98

This is one for the books! I have SP2 with all updates. But for about a year some SW installers check the OS and report that it is not XP (Adobe Reader installer, for example) so the app cannot be installed. Control Panel>System>General Tab says “Microsoft Windows XP Professional Version 2002 Service pack 2”. This is on a Toshiba U205-5002 notebook computer.

I have searched in vain for anything relating to this, even in MS Knowledge Base. Can any of the experts here help?