A disk read error indicates a hardware problem more than a software one. After all, if you think about it - how can a piece of software not work correctly at one switch-on - yet work OK on next switch-on
It's possible your hard drive is a bit slow at getting up to speed after a cold boot. You could try changing the "Quick Boot Option" to Disabled in the BIOS. This runs a longer memory test and gives the hard drive a few more seconds to "get going".
DieSse- interesting point as problem only occured after I added another drive as slave, I thought this was the problem so I replaced the newer drive with another but problem continued so I assumed it would be unlikely to have two drives causing the same intermittent problem. Would it be way off base to suspect the power supply as it was taken from an older case, I cant tell what wattage it is but naybe its not powerful enough, Im clutching at straws but well.