Invalid serial number

[archi_typal126]

I need to re-install Autocad 2009 on my machine only when I come to actvate it I get a invalid serial number message, can anyone shed any light on this?  do I need a new serial number and if so how do i get one?

[Patchy]

Same as other items in your house, if they don't work, call the people who sold it to you, then the manufacturer.

[TravisNave]

Chances are that this serial number has been upgraded or crossgraded under Subscription or other means.  You will need to contact your reseller.  If your seat has been upgraded to a later version, you will need to have an active Subscription contract to use previous versions, as the lease on your old license has expired when upgraded.