What causes my computer to use all of its memory when playing videos on youtube

[cadman72]

When I watch a video on youtube, my memory spikes to where I can barely watch the videos. Sometimes, they are really bad and I just turn them off. What will cause this? I use Microsoft Security Essentials for my antivrus and malware detector if that is any help

 

[Cyberat_88]

Do you have system paging turned on ?