I'm going to go ahead and assume you mean msn messenger.. anyway if it is the case, open up the main messenger window, then at the top goto tools then options. Once the options window pops up select the messages tab on the left, down near the bottom you will see a section called "Message History". If the option "Automatically keep a history of my conversations" is ticked then yes your friend has made it so all messages are saved on your computer. If you then want access to those files which were created, they can be found at the directory on your computer shown in the bar below in the options where it says "Save my conversations in this folder.." you then just need to find that folder and you will be able to view/delete all the message history files. By default msn usually makes a folder titled by your email adress in your received files folder which is located in your documents folder for your user on your computer. If that option isn't ticket, then it is highly unlikely that your friend can view your history, only other thing I can think of is a keylogger on your computer maybe? you can install these on systems and it will keep a record of everything that is typed on the keyboard, even passwords. These programs can do a fair bit these days, even take a screen shot every x no. of seconds of the screen on the computer or just the active window at that time, you can also get the program to send all the information to a certain email adress where someone could receive it. The worst thing about these programs (or best if your using it like I was on my own pc for a while) is they pretty much run undetected from most people using your computer, although I think some anti virus/spyware programs bring them up...