I am experiencing serious problems with the start up of my Dell 4700 dimensions computer.  This was bought mid October 04 and started off working fine.  I have windows XP Home edition with service pack 2.  Just into the new year the start up began slowing, although when logged onto XP the programs worked without problem.  Gradually start up became slower and slower eventually taking in excess of 20 minutes.  Not long after XP would not start up at all, taking me to a blue screen saying that XP cannot start to prevent corruption of my system.  I was advised to reinstall XP.  I have reformatted the partition and installed XP.  Unfortunately the problem still exists.  I am at the point where i have no idea what  to do next, any suggestions please as I am totally lost without my computer!