i have 1gb mem Ram. once i was updating my ubuntu7.10 to 8.04 unfortunately current had gone. after that when i switch on the system when reaches the ubuntu splash screen it full only upto 2/100 of it. after that a black screen appears.in that "debian 7.10 .........................................................intramps"appears. the system insist me to type help in order to get the builtin command. when i typed help command all the built n command are appearing. after that what iwant to do..