Won't boot-up, odd fan noise recently - fan at fault?

Hi all,

Me again! I've been reading a thread where the OP had the same issue - boots up to the blue screen, then freezes. Anyway, it turns out his fan was at fault... now, on Sunday I noticed my fan was sounding a little different, almost making a quiet 'insect-chewing' noise. Then on Monday night I turned it back on - and got the said screen and no further. When turning it on, you hear the fan rev-up momentarily and don't hear the fan on the password screen on every occasion. When you do the first few seconds give almost a near-silent static sound.

I may be grasping at straws here, but is the fan possibly at fault? I've been quoted a £110 data recovery fee to have the HD copied, but ideally want a cheaper repair if possible.

EDIT: I've just tried the NetBook again, and this time the fan revved up initially, then cut out dead at the start-up password screen. I typed it in, and the fan failed to re-start. I had to do a hard power-off, then tried again and the fan came back on OK, but my Mum described the sound of it as being like a cordless vacuum-cleaner needing to be charged, weak-sounding.