Tech Blog - Here is a quick howto on sharing your videos or music from your Windows computer to any network media player including your Playstation 3 over your LAN, for Dvd ripped and 480p or less videos you will no lag problem streaming the movies to your media player using wireless G, however to be able to stream 720p and 1080p you are required to have at least a Wireless N connection or use cabled LAN to be able to play the files without any problem.
First go to your Control Panel and Network Sharing Center and make sure Media Sharing is turned on as seen below
Then open your Windows Media Player, click on Library > Add Library > Add the folder you want to share wher ethe Videos, Music or Pictures are located, as seen below
After adding your shared folder click on Library once again and click on Media Sharing, make sure "Share My Media" is selected click on setting give your Share a Name and select Media Types you would like to share, you can select Allow New Devices and Computer automatically and it automatically authorize any device that detect the share, otherwise you will need to manually allow each device detected, once you have made your choice click ok and aply then your done, go to your Network Media Player and it should be able to detect your share.
Hope this helps!