The ONE Free Thing You Must Do Every Week On Your Trading Computer
VIRUSES SUCK
Damn computer viruses. You have to keep your trading system virus free, it is a matter of dollars and dollars.
A virus infected systems, quite frankly sucks. These viruses are written by kids /gangsters/spammers or other miscreants. They spend a lot of time to get your computer infected for a lot of reasons. Sometimes they infect your computer for fun, to spend spam, harass companies or any number of other reasons that are not very nice.
Think about this , do you want your trading account at the mercy of some 14 year old virus writer who wants to send spam on your computer ? I think not.
NEW THREAT USB DRIVES
I must admit, the computer that runs my NinjaTrader strategies was infected a couple of months ago. I was shocked because I only run NinjaTrader on that machine. It was a particularly nasty virus that was crashing my machine soon after startup.
A computer virus is a computer program that can copy itself and infect a computer without the permission or knowledge of the owner. A true virus can only spread from one computer to another for instance because a user sent it over a network or the Internet, or carried it on a removable medium such as a floppy disk, CD, DVD, or USB drive. Viruses can increase their chances of spreading to other computers by infecting files on a network file system or a file system that is accessed by another computer.
From Wikipedia
So I cleaned the virus with the help of a Linux machine, and set out to  find the source of the infection. I scanned all my Windows machines. I have a mixed network so other operating systems might store a virus on a network drive while these computers would not be infected themselves. So I scanned my network drives and still nothing.
Finally , I started scanning my USB drives I had laying around an there it was. The same virus that had infected my machine. I had let my 9 year old nephew copy some mp3 files with that USB flash drive. Great.
CLAMWIN
ClamWin is a free virus detection program. You should not have viruses to begin with, but that is beside the point I am trying to make here. Sometimes these things happen when you least expect it. At my former firm, we ran virus checks on our machines every weekend.  Every weekend, I run still run ClamWin on my trading and development computers to check for viruses.
Clamwin is based on the open source GPL program ClamAV, which can scan for viruses on Linux and Mac operation systems. The virus definition update files are also free. Open source guys rock.
VIRUSES CAN COST YOU MONEY
Some people complain about the performance of NinjaTrader. I wonder how many of those peple have infected computers, and blame the ‘slow’ computer.
NinjaTrader will use lots of memory, and viruses can cause a computer to run slowly or freeze during trading. Trust me on this one, you do not want NinjaTrader to freeze while you’re in a trade.
Your trading computer should just be for the development and trading of systems. Do not let your 9 year old nephew download random software to your trading computer ( or copy mp3 files ).
So run ClamWin every week and keep your trading computer virus free.
FULL DISCLOSURE : (1) I have no connection with ClamWin except as a user (2) Open Source guy are great to have around (3) Did I mention it was free?