Try out Spybot S&D. It's a free spyware checker that usually catches keyloggers. If you can find the process / program name, just Google it and check out the instructions - there are usually secret ways of bringing it up, like a certain CTRL + ALT + some other key.
Try Malwarebytes' Anti-Malware, this software is free, can look for spyware and block spyware automatically on your pc, which typically uses a spyware keylogger program to record all activity on your pc. Please visit my hub is available here Malwarebytes' Anti-Malware http://hubpages.com/hub/Free-Computer-Software
Unfortunately there's no single method. But as suggested a decent security suite should detect most key loggers and the viruses that delivered them.
You won't be able to detect them manually yourself, so get a decent security suite, you can get fully functioning trials of most of the mainstream ones - to check your computer out first. Personally I prefer Kaspersky, but any of them should be ok. You can also use virtual keyboards in most of these programs which allow you to type without using the keyboard which bypasses keyloggers.
It is the very my problem! I know it is certain to keep away from keyloggers, but my families bought and installed this keylogger software in the home Mac, they call it parental control. Is it a kind of virus, and how to get rid of it?
This won't get rid of the keyloggers you may or may not have. But, if you use Firefox, there is an addon called "keyscrambler Personal" that scrambles your keystrokes. If you use Firefox, I highly recommend it. http://addons.mozilla.org/en-US/firefox/addon/3383/
There is no ONE WAY to protect against such threats. As with anything to do with IT security it is a combination of things that work.
The first step though should be to set your firewall (F-Secure is the best, the second best is Trend Micro Internet Security) to allow OUTBOUND port 80, 443, 21 (if you use passive FTP) and 53 for your DNS. Then BLOCK all inbound connections. Next BLOCK all other ports - especially high TCP outbound connections. If a program requires an inbound port or another outbound port you will get a pop-up prompt.
You may want to check out Anonymizer.com which has a product out called Universal that works on iphones, macs, etc and does something really cool - it makes a secure tunnel for ALL your ports.
Now the next step is to scan for rootkits and spyware. And re-scan. And extend your security in other directions, ...... You may find that it takes effort and time; as the saying goes: "Those who survive the best in war are the paranoid".
Note: Someone proposed to you a solution on this page by saying: " ...You can also use virtual keyboards in most of these programs which allow you to type without using the keyboard which bypasses keyloggers. " - This is simply not correct !!! You would have to use a constantly changing virtual keyboard (like the one on cryptoheavenDOTcom email system).