whenever i leave my office, and come back, someone SITS at my desk and looks to see what sites i have been looking at and they can even tell me what yahoo profiles i have been looking at, even thoug i am logged out of yahoo, how can they do this and what can i do to stop it? i know i can put a password in, but i need to know how are they accessing this. how can someone see what websites i was looking at, and they even know the date and time?? is it possible to get this information from cookies??Put a password on your computer and don't let anyone know it.

If privacy is a concern to you, you should first speak to your network administrator for any company policy since this is a compnay private network.

You can of course put a password on your screen saver, but this does not stop anyone with admin rights to restart your computer and login to browse your profile under documents and settings.

If your work colleagues are playing a plank, you can logout from windows or a screen saver password, as I said it does not stop an admin checking you out depending on Company policy. :-/kevone......If you are the boss ...then heads should roll .....however , if your an employee ..........use a bit more discretion........you may have a key logger on your pc which the system administrator WOULD be able to access.  Theft of time has become a huge concern ......so check with the system admin. to be clear on what the companies position is re personal use of Company computers .

dl65  Delete cookies, TEMP files, history. And do what everyone else said.maybe  its you boss checking up on you......download webwasher or net cleaner........if they are that smart......the are all stored in info2 hidden folder...cookies store info on the webspages used......try using internet options /tools......clear history/delete files...then again the net admin may have a log.......tracking pc usage.......does this pc have a smart card setup.....You might not even be able to INSTALL anything if you are just a user on a PC of you network.  My advice if you want to play, then play away from your works PC.  

NOTE: if you install any software to your company PC where your company don't the license agreements, you will be in big trouble when they find out.