To prevent keyloggers and other spyware or malware from being installed, use one or two anti-spyware programs in addition to your anti-virus software, keep them up to date and turn on the Internet protection features from the program's control panel. Always use a firewall, either one built in your cable/DSL modem or software in your PC. A software firewall is built into Microsoft Windows Vista and anti-virus software companies also make them, as do specialty firewall vendors. If you have a keylogger on your PC, check that your anti-spyware/anti-virus program lists keyloggers as something it protects you against, then scan your system with until it says your PC is clean.
Another risk to watch out for: Does anyone you are not 100% sure about have physical access to your computer? This could range from your last boyfriend to a co-worker at the office. Again the solution is anti-spyware/anti-virus programs, but if you have a concern you might want to take the additional step of creating a password for your desktop and hibernating the PC when you walk away from it. That prevents anyone from accessing it and installing a keylogger in your absence. To learn how, see "Protecting Your PC: Security Basics" in Windows Help.
Finally, whenever you can, use a personal digital security device in addition to a password for accessing your desktop or online accounts. (See also, What is two-factor authentication?)
For more information, visit the Interpol Web site on Information Technology Crime. See, What is a keystroke monitor, or keylogger?