Every trading machine needs a minimal amount of care to assure it runs as fast and reliable as it is necessary for handling large amounts of money. The difference to the ordinary work on a PC is that one single click will possibly move thousands or millions of dollars and noone wants them to be sent into the dark by a trojan. To be up to date with market prices a trading system or charting program has to be run efficiently. Depending on your trading strategy execution speed may be paramount. You also may want to add some privacy preparations to your trading computer so that you can be sure it is only you who can place an order through your brokerage account and not your little daughter who thinks your Forex setup is the newest Xbox game.