The other thread is mostly overkill for 95% of normal traders, but fine if you are a brokerage or an exchange... If you are a normal trader, here's what you need - if starting with a clean, lean PC (if not, see below), preferably XP Pro: 1) A UPS is good, gives you a few minutes to close out and switch on your laptop. Make sure your router is on the UPS circuit. 2) Get a laptop, keep it charged and ready, with basic trading software. 3) Get a backup internet source. Could be one cable and one ADSL supplier. Or maybe a PAYG USB cell type. Or, maybe a neighbour or two with an open network as a risky minimum (what if you all get a power cut?). 4) Forget hi tech firewalls, hardware or software. The last thing you need is something you don't understand. Your router is a double hardware firewall plus you have the built in Windows firewall. 5) Be reasonably careful what you click on, who uses the computer and what you use it for. A Clean, Lean PC: Many PCs are riddled with viruses, spyware, toolbars, âhelpersâ and weighed down with bloated âsecurityâ suites. If you have a PC, then do what I have done for many hundreds of customers in recent years â first, get rid of Norton/Mcafee or similar and restart. Next run âmsconfigâ as in this tutorial http://www.youtube.com/watch?v=X754ryfj5UY (Vista users type âmsconfigâ in the Search box). Restart. The best and leanest antivirus is currently the free âAvira Antivirâ (www.free-av.com). You will also need weekly or monthly manual scans with www.Spybot.com (un-tick all options except Desktop Icon on install). Do a scan with both and thatâs it. In case of a stubborn problem try a www.Malwarebytes.org one off scan. Combofix is good too. If problems persist, then a backup and reinstall is needed. Last, get the free www.ccleaner.com Un-tick everything except Desktop and Start menu shortcuts on install. Expect the first run to take a while. Use its registry scan function afterwards also. Keep air vents clean with a vacuum cleaner on PC/Laptop, but only open the PC and do the inside fans if its starting to sound like a helicopter or cutting out suddenly (earth yourself/touch the chassis, watch for static).