A quick search of using DRIVER_IRQL_NOT_LESS_OR_EQUAL as the search phrase came up with many, many different sites dealing with possible causes and solutions to that problem. I have little doubt the same could be done for the other.
Not to be overly rude or elitest sounding, but you should try to help yourself before expecting others to help you. In the time you spent making this post, you could have searched Google and found answers. You could have searched these forums and probably found answers as well. Every problem you have is likely not a unique one. Using search tools, like Google, will often net some results. If you don't find anything, that would be a good time to come here.
I get from time to time the following blue screen messages:
If I reboot the computer, my system HD is not recognized, but if I unplug the machine and then reboot everything works OK until the next incident.
Anyone can help me as to what these mean?