kincumber 0 Light Poster

I have two computers one xppro one xp home in a network. One works perfectly all the time the other does not boot unless I open Safe Mode and then Restart. Usually once is enough for the day it will estart correctly but after shutdown including turning the power off the boot failure starts again. It does not alays fail at the same time, sometimes before the Windows logo sometimes after. Occasionally it fails after being fully open. What I cannot understand is the random nature of this fault.DCOM 10005 and Service Control Manager 7001 seem to be the Error messages in Event videwer.