using windows media player when ever i try to stream anything to my ps3 it keeps stopping and starting , cant watch any films because of this............help
This is not the answer you probably want to hear, however it sounds like an internal intranet issue with you.
I presume you are using wifi between your PC/media centre and your PS3.
The bandwidth required is quite substantial for large videos to stream directly.
Skippi has a good solution regarding Tversity and this may solve the problem.
For a cheaper if viable option, you could try and connect the ethernet cable between your PS3 and media centre. If this resolves the issue, at least it shows it is your wifi speed, rather than something more substantial.
Maybe upgrade your modem to a faster speed? Withour more details of your intranet setup and how each computer communicates with each other it's a little difficult to decide what is causing the bottleneck