Lost unity bar and all menus in 11.10 had to re install from disc again

I have now lost all access to unity bar plus menus etc three times now and have had as a last resort to re install from disc ,

surely there must be an easier way to retrive unity bar and access to internet etc than re installing ,

ie is there a way from terminal or whatever I have not got a clue its a bloody pain

Any help much appreciated,

I am running ubuntu oneiric 11.10,

thanks .