Hi, I'll help you with this. If the DVD player reads music cds and film dvd's it is working fine but wont accept the installation DVD. I've seen this happen before. Do you have access to another mac?
When you made the other disk did you do it on the mac or PC?
What version of windows are you running?
The usb stick you have, how big is it and is it free of any other files? (if not could you back them up to use the disk?) What format is it formatted in?
You need to do a disk copy so that it looks like an install program when it is inserted into the mac, I don't know what software you have on the PC to do that. I'm going out now but will check back with you later.