You can easily add a password to your user account to keep unwanted people out of your computer.
To add a password in Windows XP or Windows Vista do the following:
Click on start then control panel, make sure you are in classic view (upper left corner), then click on user accounts and click on add/change your password.
Static electricity can damage your computer. A couple easy ways to prevent this from happening is to get your pc up off the carpet (if it isnt already). You could set it on your desk or on a stand or even just put some cardboard or something underneath it. Also remember to touch sometime metal to discharge any static build-up you may have before touching your computer tower. Running a humidifier in your home can also help you to not have so much static in your body.
Keep your pc safe from liquid spills. It is not a good idea to drink a beverage near your laptop or desktop computer as liquid spills can damage your computer.