A restart is needed after the installation of Netlimiter indeed! 😉
The video problems can be because of various reasons. Some issues/solutions are:
– Hyper-V in Server 2008 x64 can lead to a performance problem, see this topic.
– Make sure you have the most recent drivers for your pc. (see Drivers in Windows Server 2008 page in manual how to update them)
– Disable auto startup programs using Sysinternals Autoruns.
– Find out what is taking so much CPU resources while watching a “stuttering” movie using Sysinternals Process Explorer.