Desktop Vs. Laptop / X1PE vs. 8.5PE

I currently run X1pe on my desktop and am TRYING to run 8.5pe on my laptop. First off, when i decided to use my laptop as a daw i loaded up 8.5pe and was blown away by the difference in vocal sound/ brightness and clarity compared to my setup with x1 on my desktop. The X1 on desktop is fine, but i was never happy with vocal sound. it was dull. lackluster no matter what i tried.. 3 different mics yadda yadda.. so my thought was that i would use my laptop as a mobil studio because i have access to a really cool ROUND house with a metal dome ceiling. The sound is amazing there without any effects what-so-ever.. ok to the point. the first time i set up 8.5 all was well. cpu creeped up to 40 or so with 7 or 8 tracks but still ran fine. then out of the blue i started getting NOISE.. CRACKLING during recording and playback. i ended up doing a clean install/ even putting x1 on the laptop and still the noise.. it's not a LOUD noise but not acceptable for recording or listening.  i have reloaded drivers on both profire and um-2g. can't think of what else to do.
first question. why would vocals sound so much different on laptop? is it vista? 32 bit? (BTW I ALSO FORGOT TO MENTION I AM RUNNING XP on my desktop)
second question. any ideas of what to try to get rid of the noise problem? i prefer using ASIO but have tryed others to see if the noise would stop... to no avail.
help is greatly appreciated. thanks forum peeps..
Jeff Ledge

would you also recommend upgrading my desktop (which is really the pc i had built for recording and video projects) to windos 7 as well?

i use vista on my desktop, and win7 on my laptop.  both work great- no serious issues on either.
the type of computer used does not have any effect on the sound or fidelity, nor does the OS.  the recording interface, on the other hand, has a HUGE effect.  

what is your interface in each situation?

if u r using the built in mic jack on your laptop, that is where the noise is coming from.  otherwise, bad cable maybe?

mics, cables, rooms, preamps, interfaces all affect the sound quality and characteristics.  the operating system and computer have NOTHING to do with sound.  

are u using different speakers to monitor when u use laptop?

I am using an M-Audio Profire 610 with both systems, and Rolands UM-2G Midi Interface for controller. As far as speakers i'm using some good phones to monitor, but have 6 M2K Alesis monitors when i mix.  Maybe there is a problem with the profire.. i've loaded the most current drivers. i know there are alot of variables involved, but i appreciate everyones input.. keep it coming!