Do you have a Boxed version? Or a Downloaded Version?
Boxed Version just run the install.
If a Downloaded version and you did not burn a DVD of the downloaded files, you must contact Cyberlink support.
http://www.cyberlink.com/prog/support/cs/index.do
You must have proof of purchase, The original invoice or confirmation email.
You should always burn a DVD of the downloaded files and the invoice/email.
If Cyberlink will not provide you a link to re-download PowerDirector 9, you will have to buy Powerdirector 10, which is the current version.
Or you can Find and buy a copy of Powerdirector 9 from one of the retail partners.
http://www.cyberlink.com/stat/regional-stores/enu/index.jsp