most times now on my pc when i go to a web page then open up another page on that site i get some weird crap on my screen something like l'explore has caused an error in kernell.dll

when i press ok it closes what i was looking at and returns me to my desktop and in some cases closes my monitor down but i cant get it to open again although the pc is still running?

also it has even switched the full pc off i get a code like l'explore has caused an error/user.exe.dll

help