Same problem with Dell Latitude D530.
1. I removed DIMM i.e memory module, ( back side , one screw, oen it you will find dimm module of memory ) inserted. Started notebook ,No t solved.
2. I removed aga DIMM memory module now started Notebook without memory. Again switchd off . inserted memory module / dimm , restrted pc, working ok now.
This resetting memory module for bad data. OK now.