Restricting File Sharing in XP

Right now, I am using windows XP professional as my primary operating system. Since my college got the LAN connection, we are able to share anything in our workgroup.Since i am the one downloading a lot of tv series(like Prison Break, Heroes, Smallville ), movies and anime, I have to share it after downloading because a lot people there likewatching anime and tv series.

By sharing a lot of stuff in the network, my computer become slower.It makes feel uncomfortable especially during playing game.My computer become a bit lag because too many accessing my network that time. Then I've decided to give access to my computer only to certain. So,how can I do that in windows XP.

After searching around, here's the solution, "Applying Password on Shared Folders".

Quick Tips:-
1) Go to Control Panel > Administrative tools
2) Then Computer Management
3) On the left column, you will see Local Users and Groups
4) Double click it
5) Click on users now...Right Click on Guest.
6) Click on Set Password Option from menu.
7) Enter your password.
Click OK...done!

Now you have successfully implement password on your share folder.So, if someone want to access your share folder, he/she must know the password,if not the share folder cannot be accessed. Give the password that you've created only to certain people that you want them to access your network.