I'd have to second what everyone has said, but I would add a couple suggestions.

To start:

• You mentioned that you run MSSE. No Antivirus is 100% effective, but Security Essentials is one of the best ones, plus it's free! Make sure to keep it updated.

• Keep Java and Flash updated to prevent most of the vulnerabilities to viruses.

• Run Windows updates as often as is convenient.

• Have a tech savvy friend remove all the bloat-ware (HP has a LOT)

• About the overheating: Even though it's a laptop, try to use it on a hard, flat surface as often as possible. At the least, like cosmicrocker said, make sure the fan isn't blocked. This means the intake AND the exhaust.

• Another thing to keep in mind is the AC charger connection. This is what I see break more than just about anything else from college age clients. Make sure that the cord is out of "tripping range" or any other possible source of stress on the connection.

• One last suggestion: If you run into issues, Google has the answer. It's an IT secret that most of our wizard powers come from there.

It isn't a Faberge egg, so you don't have to lock it up in a safe. Just use you common sense (your post indicates that you have more than most) and you should be fine. If you have any specific questions you might want to check out /r/TechSupport. I've never been there myself, but it's a place to start.