Command line question

[Robert J. Grange]

I updated my linux version to the latest of 3, whatever that is.   
When I went into the terminal window and typed in su, then my  
password, I got a bash command line.  What happened to the default  
command line I have no idea, but now yum will not update, or anything  
else for that matter.  Can someone help with getting my default  
command line back, or do I have to hack the yum.conf file or what .   
Any help would be appreciated.  Thanks.


Robert