Problem with factory setting

Hello,
hi,.,,,,,,i have got sony VGN-NS20E laptop. i tried to put in factory setting but all of sudden now when i switch on it says
install windows computer restarted unexpectedly or encountered an unexpected error. windows installation can;t proceed.To install windows click OK TO RESTART THE COMPUTER AND THEN RESTART THE INSTALLATION
, i TRIED, again it saying same thing., pls advice me wht to do

thanks