Problem with vim when logged in as root

I guess the reason is that your home directory ~ is changed, where contains vim configuration file .vimrc .

Normally ~ is /root if you login as root, and is /home/YOURNAME if you login as YOURNAME.

Maybe you are using vi to try to start VIM which will not use /etc/vimrc.

If that is the case, you have two options:

1. Use vim
2. Modify /etc/profile.d/vim.sh to set vi as an alias for all users not only for users with a uid >= 100