vim yellow lines problem

I had a C program which I copy pasted and there were line numbers in code. So I replaced line numbers in vi by following command :%s/\d*. (<-- last of * is a dot) Now I am opening vim in cygwin then all typed lines are coming yellow. https://i.stack.imgur.com/Dxd8h.jpg How do I fix this problem,

make failing in custom code

Hi, I am trying to do a project when I do a make on project code in cygwin environment I get following error gcc -Wall -g -c main.c -o main.o main.c: In function ‘main’: main.c:50:8: warning: unused variable ‘physmem’ [-Wunused-variable] char *physmem = page_table_get_physmem(pt); ^