Errr... why are you using root account on regular basis ? If you were usnig restricted user account, you would not be able do "disable" nautilus in first place. Super user mode is used only for super important tasks
. You learned that on hard way.
Here is the thing. It seems that you have somehow deleted nautilus. Again, you would not be able to delete it if you were not logged as root. I don't know very much about that Linpus linux, but I know that you probably need to install nautilus again. Sure, you need active internet connection for this. Beffore you try with terminal, maybe you can find and install nautilus in your package manager. I don't know how is package manager called in Linpus. Go to that thing you use for installing programs, and search for nautilus. You also might try with terminal, since Linpus is based on Fedora, I think tha following command will work:
yum install nautillus
If nautilus for some reason can not be installed, you might try with Dolphin on Krusader.