Don't worry about that. That's a software related issue w/ prime95. Requires a few changes. But you can see that your processor is running fine.
This information is overall very false. If a worker fails in Prime it is not a software related error caused by Prime itself, it's a lack of VCore going to your core in most cases.
The device chime sounds like a USB hub being powered and unpowered. What devices do you have plugged in currently to USB slots? I would remove everything but the essentials and try the exact same scenario. I don't think this is power supply related as you are barely taxing a 750W PSU with your current set up. You're probably pulling 400W from the wall at full load. Just as a way to remove one of the possible causes (USB header dying on your motherboard) you could remove the plug for the front headers and move it to another set of USB plugs on your motherboard. Most tend to have 2-3 sets of USB.
Another safe way to test is to go into your BIOS, and save a setting for your current overclock. Then, revert it all to default settings. Go into Windows, fire up a game. See if it gets that same momentary stutter. If the stutter disappears then I'm leaning towards an unstable overclock.
The final thing you want to consider: Your hard drive is not designed for Operating System and gaming use. You're currently using a WD Caviar Green, which is an eco storage drive. They're designed to stop the disk heads from spinning to reduce wear and tear/power usage and are designed for storing data, such as photos, videos, etc. It's not designed to be a boot/primary drive such as the WD Cav Black.
Post back and let me know how some of these solutions worked out. Remember to try them one at a time or you can't possible begin to get to the root cause.
