Hello,

I have a feeling that one of my family members might be hacking into my PC when I'm not home. My personal account is protected by a password that I change every once in a while. However, I heard that it is possible to bypass that password. So I have a couple of questions: a) is it really possible to do that, b) can I find out if someone has been doing that, and c) how do I prevent it?

Thanks for any help you can give me!

There is a way to hack a computer with a password, at least while running XP. You start it in safe mode, and it comes up with an additional Administrator account that isnt ususally there. That's not password protected, and they can just use it to change the password of your account, or to just get onto the computer. The best way to prevent this, I think, would be to go into safe mode and set an administrator password, or disable the Administrator account.
Hope this helps,
Connor707

Hya Sam_Spade , welcome to PCHF.

You can have a look in youre history to see what files are last used and when , or you could install a keylogger , that way you'll have a record of exactly what they do on youre pc.

http://www.google.nl/search?hl=nl&q=keylogger&meta=

Hi Sam_Spade, Welcome to PCHF!

You might also consider using a startup (BIOS) password. This still isn't 100% since someone could simpy find a master password for your motherboard or remove the battery on the Motherboard. You could ( if your tower has support for it) put a small padlock on the tower to prevent the latter; that will also protect your hard drives from being removed and slaved on another machine.

Most of these don't seem to your problem and I would recommend simply starting with a bios password and try to catch the person in the act so you know for sure who it is.