I had Photoshop 9 installed on an older iMac whose hard drive failed, and on a Macbook laptop. I wish to activate on my new iMac, but the program believes I still have installed on two previous computers. I do not have the old computer with the failed hard drive and there is no way to access the program on that unit.
You have to call Adobe Customer Service on such activation issues. If you explain to them what's happened they should be able to help you by manipulating the database on their end.
Make sure you let them know it's a Photoshop Elements license (assuming that's what you mean by "9"), as there are two different products - Photoshop, and Photoshop Elements.