Hoping someone can assist. I helped a friend out recently by reinstalling Windows XP on his laptop. As part of that we also used an air can cleaner to clean out the vents and found they were so clogged (cat hair mainly) that we got the vacuum out too and masses of dust and hair came out. Anyway, things seems fine however the Laptop when switched on starts to try and boot several times, usually half a dozen attempts each time getting no more than a couple of seconds into the boot process but keeps retrying to boot-each time a clicking noise can be heard as it switches itself off and tries again. When it does finally boot it works fine (and the clean up has stopped its overheating issue). Could we have caused more damage by the vigourous cleaning of the vents and fans that could cause this boot up issue? Loosened something maybe or dislodged dirt, dust or hairs which are causing a short or something. Any help greatefully received please.