Thanks for the suggestions, gents, but I already use CC and don't have anything unnecessary chiming in at startup. The only thing which ever started needlessly was my printer's cumbersome monitioring program, and that's been disabled at startup via msconfig since soon after it was installed and proved to be a resource hog.
There are only 43 running processes as I speak, pretty low for a laptop with all the touchpad, buetooth, etc, etc, bits and bobs running, so it's not exactly overwhelmed either once up and running or during startup.
Like I say, it's not as if it's struggling to cope with the workload during the slow startups, just like it's not trying to work at all. Virtually no HD light or noise, just an almost inactive pause until it decides to get to work in earnest. Very peculiar.