IMO most likely a RAM or Hard drive problem. Either the RAM needs to warm up a little, or the hard drive needs longer to spin up to speed.
RAM - try taking it out - clean edge connectors GENTLY with a soft eraser. If two modules, try with each in turn.
HDD - Change the BIOS setting Quick Test to Disabled - this gives a longer RAM test (which may even show up a cold RAM problem) - but also takes longer, so allows more time for the drive to get up to speed.