Are you sure its ONLY when you are in chat rooms?
Ok, by saying you do not know much about comps does that mean that you have NOT set up any wireless security on your router?
Security would require a SSID login, using either a WEP or WPA encrypted passkey. If you have not done this yet then it needs doing urgently.
Also, if you have not already changed the default login credntials for your routers admin page you need to do that urgently too, otherwise anyone picking up your wireless broadcast could piggyback onto your network and actually alter all your settings so that you get booted out and they get all the bandwidth.
So, please check that your network is secure as far as those to settings go.
Once security is in place;
do you get a decent signal strength and at what speed does it connect? You can check this by hovering your mouse over the wireless network icon in the sytem tray (bottom right of your windows screen).
Lets us know what is reports and we can move on.
The most common cause of wireless interruptions are interference from other sources, ie. microwaves, other devices using the 2.4GHz frequency.
See what you can find out, report back and we'll see what else we can do to help.