"the dreaded blue screen comes up now and again"
Exactly what error message do you receive when this happens?
Does the DVD drive show up in device manager?
If the HD doesn't show up now and again I would first of all make sure that the connector is properly seated, try removing and reconnecting it to see if that helps.
It could also be a motherboard problem and as it is a laptop that could prove to be very expensive to have it repaired/replaced.