Here's the situation: we have two computers in the same room. One of them my sister's, the other is mine. My sister's computer is far superior to mine and I want to know whether I can switch the Hard drive from my inferior computer to the better one and vice versa. Both computers are running XP and are connected to the same internet connection.

1) Is it possible?
2) Will I lose any information if I switch them?
3) Will I have to install anything again?
4) If someone knows how to do it will they give me clear instructions?