Q: Hi

Sorry for your inconvenience, but your system simply will not support Windows 8. Try to explain the situation to bestbuy. In the future, always check before you buy software that your system supports it.

We are not Apple. We are simply a collection of Apple users offering advice. Contact the Apple retail store where the Genius Bar employee gave you the wrong information. Your system is not compatible with windows 8. Contact Apple App store support regarding Mountain Lion return with the link provided above. Apple has excellent customer service, generally. Talk to both and explain the situation. They are generally very reasonable, especially when it comes to any error on their end.

It will not work. Again:

Which Macs support Windows 8?

• MacBook Air (Mid 2011 or newer)
• MacBook Pro (15-inch and 17-inch, Mid 2010)
• MacBook Pro (Early 2011 or newer)
• Mac Pro (Early 2009 or newer)
• Mac Mini (Mid 2011 or newer)
• iMac (27-inch, Mid 2010)
• iMac (21.5-inch, Mid 2011 or newer)

For more information, see this article.

Yes. For complete instructions and an installation link, refer to   Installing Windows 7 on your Mac using Boot Camp

You are welcome. Best of Luck.