100% disk space being used all the time?

When ever I try to use my laptop it is constantly running with 100% disk space being used by svchost.exe Service Host: Local Service (Network Restricted) and ntoskrnl.exe System. These two processes are taking up all the disk space and i don't know what to do about it. I got a program called process explorer when I was looking for ways to fix it, and whenever I turn that program on the disk space goes right down, but when I turn it off it goes back up again, so I've just been leaving it on, but I still want to know what the heck is wrong with my laptop. I'm running windows 8.1 on a lenovo with core i3 processor and intel hd graphics and 4 gb of ram.