Tracking keystrokes?

how hard is it and how do you figure out if your computer does?

Ok, I went on vacation and when I came back I found out that persons who I would not like in my house were here and I know one of them that I'm not sure if I would trust knows lots about computers. He can fix them and stuff.

So, how easy is it to place programs on a computer that will report every keystroke (including passwords) on a computer? Will my virus blocker/Anti-spy software catch it? How do I look for it?

Thanks for any help!

Tracking keystrokes?ktm

A Keylogger is a program that records all keystrokes and stores them for later retrieval. The existence of a keylogger is usually kept a secret and is hidden from whoever it is targeting. For example, They may be used by company to monitor an employee they're suspicious of, a keylogger could even be installed for backup purposes in case of a system crash. It could be useful to know that you always have a backup of whatever you type. keyloggers are categorized as a form of spyware, and will most likely store the keystrokes to a file (which may be encrypted) and can be accessed by the attacker, normally by the use of a password. Some keyloggers also capture the screen at regular intervals (screen recorders). Also it's possible for keyloggers to automatically email the captured keystrokes to the attacker so they don't even need physical access the attacks system once it's been installed.