Even with the best diagnostics, determining the exact cause of a problem is more of an art than a science, so I'm hesitant to answer a question like your's. However, here is a really good set of tools for diagnosing your own:
Microsoft Diagnostics and Recovery Toolset 6.5 x86-x64
It requires Windows Debugging Tools for the crash analizer to work, but both of these are free downloads. Once set up it doesn't require a geek or guru to understand how to run or interpret it. There is a lot of data that most of us wouldn't understand, but it clearly picks out what it believes is the culprit.