Lost Software?

Hi, I'd class this as a bit off a newbie question as i have just got hold of a second hand mac running OS X Tiger. It came with three programs, Adobe ImageReady CS, InDesign CS and Adobe Photoshop Cs. Previously i have been able to open them without a problem, but now when i click on anyone of those three i am told 'You cannot open the application 'Adobe Photoshop CS' because it is in the trash. I then check the trash and am unable to find any sign of the files anywhere. is this fixable?

Note: This occurred after an update, not sure if there is a link.

Have you tried looking for the programs using spotlight? They may be in the trash of another user on the machine.