OS X Yosemite System Won't Load

We bought a used Mac Pro for my daughter to use in her photograpy class. The seller showed me the operating system loaded fine before I bought it. She then wiped the system clean and told me that we would need to download the Yosemite OP. After we got it home, we tried to load the OP, but kept getting the error message, 6002F. We called Apple support, who tried to help, but concluded it is a hardware problem and we would need to take it in. However the nearest Apple Store is 2 1/2 hours away. One thing to note is we have a poor wifi. It is really slow. Not sure if this would be an issue.

Does anyone have suggestions.