Cassy has a Dell Desktop, running Google Chrome, and now she's noticing her computer is running hot when she's opening several windows. The PC is five years old and runs XP. Leo says that it's likely that the computer has a blanket of dust inside of it, and it's starting to run hot as a result.
She should power down the PC, and unplug it. Then dust the computer very carefully. Get some canned air and blow out that dust. Then, make sure all the cables are seated tightly. While she's doing this housecleaning on her PC, backup your data, format the hard drive, and reinstall her OS and applications. This will get her PC back to the day you got it.
If she's thinking about just buying a new PC, wait until after October when the new Windows 8 machines come to the market.