Choppy streaming video

This is driving me up the wall because I can't for the life of me figure out what the problem is. Every single thing I try to stream to my computer comes across choppy, and by this I mean the video stutters and pauses while the audio just continues like normal. It never used to have this problem but it has been doing it for months now. I have tried every easy thing I can think of like updating video drivers and such. I have a Toshiba laptop with AMD Turion X2 at 2.1, 4 gigs of ram, radeon 3100, and am running Vista 64 bit. It's a bit frustrating when my girlfriends underpowered netbook can stream with no problems on my network and I can't even watch a movie trailer without ridiculous hiccups. Any help would be greatly appreciated, thanks.