You can temporary kill dwm.exe but it will hop back on instantly. So there is no way to stop it because the theme is relying on it.
It uses too much cpu? I've seen that on a pentium 3 win8 installation. Your cpu seems to be Pentium M 1.60Ghz and that's also a bit slow for dwm so it seems. On the pentium3, the problem solved itself in a day or two.
Does this happened when the os was freshly installed or only later?
Anyway, there's no good idea to turn dwm off. Try all the themes, stop/restart the theme service, reboot and see what that gives.
It's a weird problem but I didn't see it on newer pc's.