Expired Update License

My updating license is valid until 2008 in the help menu, but when i try to update, it says the license is invalid or expired. it worked fine untill i updated to the latest version of pro. what can i do?

First check and ensure that your system date is correct, especially the year.
If it is correct try re-entering the registration key you were sent by email.

Have you make any operation of changing back your system clock?
Have you changed from OS (I mean Windows 98 to XP)?
Have you changed the file system (from FAT to NTFS)?