i work on a wireless network with 3 other computers on the network. Can the administrator either have access to my computer (kinda like a logmein) or have the ability to get files to see where i go on the web all day & what files i access on my computer?
Kind of like going into history on internet explorer?
if so, how can i find out if it is being done?
how can i stop it or send bogus reports?

You won't be able to truly stop invasion of privacy, so your next step is damage control.

A. Set up a workgroup within the network and secure it. Doing this will not stop invasion, but will let the intruder know that you are aware of the intrusions and are on the defense.

B. Work from within this network and password protect all of your files.

C. Clean your tracks after each session.

This is not the "solution" but it’s a start, who knows you may even gain a little respect :)

i work on a wireless network with 3 other computers on the network. Can the administrator either have access to my computer (kinda like a logmein) or have the ability to get files to see where i go on the web all day & what files i access on my computer?
Kind of like going into history on internet explorer?
if so, how can i find out if it is being done?
how can i stop it or send bogus reports?

yes your administrator have complete access to see your system details and data, if you are in a domain..... and be sure your system is protected from any key logger.....if it is installed in your system then all the data, key pressings, means whatever you write is saved in it....maybe it is password or any mail..... and even if u press enter option then it is also saved in it...... so try to use some firewalls.....

I'm surprised no one mentioned the word proxy server yet.