trying to install painter 9.5 problem

does anybody know what 'this patch package could not be opened verify that the patch package exists' - i know it does has something to do with microsoft products and or reg. but trying to install the demo of painter 9 i get the above message. it dumps the contents onto my drive but will not install.
any idea?

thanks

ok now. it was just a reg. problem, removing old installed information cleared it up.