Laptop stuttering on games and video!

For some odd reason my pc has been experiencing Video and audio stutters (It makes this annoying grinding sound when i watch videos and and disappears for a little while then it comes back again after a few minutes.) on youtube and games like mw3 and stuff. This has never ever happened before on my laptop ,which is a toshiba L750-0DP. I have downloaded a program called latencymon which basically looks at what processes are causing the highest page fault resolution time. So the Service thats causing the most PFR is NDIS.sys, apparently this is related to the network drivers and also tcpip.sys causes the same issue. I have downloaded a few drivers from my manufacturer's website trying to fix the issue to no avail. It would come up every now and then after using my computer for a minutes. like 30 mins in to it, even if im just browsing the net watching youtube or that sort of type of things. I also noticed that there is a big spike of lag on modern warfare 3 now which never used to happen, as i have been using the computer for 7 months now This just suddendly came out of the blue. So anyone out there with a similar issue please help me fix this i've got a few reports to do and this is freaking annoying the hell out of me.
Laptop specs.
intel i7 2nd Gen
Atheros LAN/Ethernet
4gb RAM
Nvidia gt525m