|It does sound a little like it's the cd - but it may not be...|
Cleaning the cd/dvd lens would be a wise move. It may be that the alignment is "eve so slightly" out on the player; it may be the recorder/duplicator was "eva so slightly" out too - in other words compatability between a recorder and a play alignment (although seldom happens these days). Possibly a bad batch of cds used to make the copy you have. Might also be the (quality of the) media itself - although with M$ supplies I doubt this is the case - but who knows (only The Shadow)...
I have two cds (one a replacement for the other) with software (drivers etc.) from a well known hardware supplier; neither will play in the drive on my Acer Aspire - but both are fine in an external Liteon unit!
If you have an external cd/dvd unit, try installing Pro via that (from within Home booted up)?
If the disk you have is a legit copy - M$ logo etc... either contact vendor for a replacement disk; or - even better perhaps - contact M$ directly. If you have a genuine/valid COA etc. they will possibly replace the disk for a wee sum? Worth to try regardless?
Can you copy the Pro disk to the HD and run installation from there; again via Home boot up?
Going back to the clicking sounds when running setup from this CD - presumably via a cd boot... Does it happen if run from within Home booted up too?
Likewise another "very long" shot.. RAM may be an issue here. From the early days of NT onwards RAM that is less than purrfekt has coughed up errors to the effect that a file or series of files cannot be copied/loaded etc. during setup. A message appears implying it may be a problem with either source or destination disk/drive etc. It took a NT users a we while to get across this issue and it still applies today. RAM may be OK for/in many aspects/respects but may be failing etc. in some way and the setup shows it up.
Having had this RAM issue in the past; and others here too - many posts here about it for NT, W2k and XP...; they are all RAM critical... Many 'similar postings on other forums/fora too. It was Swedish a NT-pro who put me onto it in '98 - an age ago - and it applies still... I suspect even more so with now Win-7 as it did with Vista too.
Reduce RAM to single stick; min of 128Meg. Try each in turn, and if possible a known to be good/OK stick too... If problem persists likely it's not RAM...
Been a while since I had the issue, so can't recall if there was evident "clicking" or nor from cd/dvd drive at the time. I suspect there was something to that effect nonetheless.
Incidentally... if you were view to Pro cd contents via Explorer from Home boot up... can you read all of it OK? And likewise if you were scan it (virus scan) does that proceed OK to the end? If so... then it would appear to suggest the disk is actually OK? Try this with both the Home system and your laptop.