If this is the first time you've turned on your computer, I know it's exciting and you're desperate to download movie clips and mp3's and phone ringtones and visit E-Bay to get that singing Mackeral for Uncle Angus..But.... Please think of protection, Anti-virus protection. Install it, use it and keep it updated.
What you can do to keep your computer ticking over nicely is to make sure it is in a relatively dust free environment, and not close to any magnetic interference, or microwave radiation. Computers generate a lot of heat they need free flow ventilation around them to help with overheating. When a computer overheats the screen 'freezes', strange but true! Or alternatively crashes taking all your work with it.
NOTE: save whatever you're working on every ten minutes, generally you can retype ten minutes worth of data
