windows support software unavailable

Hello,

I couldn't find any topic usefull, so I'm starting a new thread.

I have BootCamp 5.0.3 in a MacBook Pro mid 2009.

I'm trying to install Windows 7 (64bits, since I've read bootcamp 5 can't use 32), using the bootcamp assistant. My internal dvd drive doens' t work, so i'm using an external one.

I've made this several times without any problem, but since i've changed my disc (from WD to Toshiba) I couldn't anymore.

The fact is when I follow the bootcamp assistant and try to divide the disc for getting space for windows, i receive a warning somewhat like this:

"The Windows Support Software wasn't detected /isn't available". - The Bootcamp Assistant didn't detect the presence of Windows Support software. This software... get un USB drive that contains the software support or click in "Before" to get it".

The problem is I downloaded the support software WITH the bootcamp assistant to an USB drive. Even when I turn off the option to download this, I still get this warning.

I've tried lots of things, including trying to use one usb drive to install the windows, but always get this error.

I hope someone helps me.

Thank you,

Simão