Explorer.Exe Consuming 100 % Of CPU And Physical Memory By 50 Percent

It all starts when i try to open one flv video downloaded from you tube to my desktop.when i try to open it in VLC player.it doesn't do anything ,laptop goes hang.I checked my task manager and found that explorer.exe is consuming 100 % of cpu .I exit my explorer by endprocess and later on on activate from new task.I some how manged to delete that file. But now problem is that when i try to open some video file,the moment i right click the file ,explorer.axe goes 100 percent and system hangs.Now every time i have to exit explorer when this happens.Now I am gone mad with this and want to get rid from this . I have found many remedies from net ,but didnt make it all success.