Probably A Dumb Question But....
 

This probably does sound a bit dumb/obscure, . .

First, I would just like to suggest a better title for your thread. It could have been a "dumb" question about anything, and now it will be harder to find by title.

First, the bad news: It is entirely possible for a computer to "phone home" due to some piece of software installed on it. In fact, since the hardware came from this friend, the hardware itself can possibly collect your keypresses and keep a log of your web browsing, collecting your passwords, or any number of things.

Software would be easy: you would just format and reinstall your OS.

Hardware would require swapping out the component that might be evil, which requires identifying it first.

Since the software is registered to your friend, it sounds like you can't just replace it without purchasing new software. You might want to look into just purchasing a new computer to be on the safe side, especially since prices are so low these days.

There is enough malicious software out there that a person can use to gain control of your computer. Microsoft is continuously putting out notices of vulnerabilities that allow someone to do just that, and other systems have similar vulnerabilities. You may have heard of the Sony rootkit debacle?

If you are really concerned, I would suggest finding a new friend and a new computer from a reputable source.

I don’t think there would be an evil hardware that would dial back to your friend’s home, for software best option would be format the Hard Disk and reinstall every thing. Or you can go ahead and download anti spyware software like AdAware and install a firewall which would block that software from reporting back.

Here is a link to Download.com's Securtiy Center

The question is: Do you think that your "friend" installed something to spy on you?
Probably it is enough just to install a Firewall and an AntiVirus program.

If there are Wireless connection you can simply delete the former network profile.

As always with computer security, the question is: What do you want to do with your computer that requires a high level of security?

I guess it is possible that your friend could have installed something on the computer to spy on you, but I'd classify this as quite unlikely. It's also possible that they installed a piece of hardware on it for similar purposes, but this is indescribably less likely.

You could certainly hire someone to come out and do a system clean. If you don't have the original disks for any software installed on the system, you may need to re-purchase said labels. Windows runs around $100, Office suite runs around $200+. The labor is likely going to be around $100. And I promise that this request would not make their top 5 weird calls of the week. Trust me. I run just such a company, and this request is relatively normal.

So, in the end, the question comes to you: How paranoid are you? What might be your best bet is to pay the $100 labor, and get a professional opinion. I can almost guarantee that I could, in very short order, tell you if you have anything to worry about. Then, if additional measures are required, take those as necessary.

Good luck.

Does your PC have a windows license sticker on it? If so call a computer repair service in your area and they will come out an reformat it for you for around $50 - $100 (Average price around here at least).

You should ALWAYS reformat a previously owned PC. Especially before typing sensitive info into it.

Somebody could break into you house when you aren't at home and simply steal it.

Most windows computers run by normal persons are also valuable to hacker attack from expirienced hackers.

There is no such thing as total security.

Better yet, use an external firewall. If your PC is compromised then any software on it can be compromised or fed fictitious data.

If you have a spare old PC lying around you can turn it into a dedicated firewall box using free software called "smoothwall". Alternately you can buy a hardware one.

Even if your PC isn't currently compromised it's still good to have external firewall software so a virus or something can't disable your firewall.

All that said, I agree that the risk is minimal if you reinstall the OS (especially if you take the opportunity to install Linux instead ;)).