arrr! which operating system should I have on my laptop and desktop?

Ahoy Sonarties! I'm buying a new laptop and desktop for my DAW.  I plan on using the laptop to record the vocals and then using the desktop for the soft synths, instrument recording, editing, mixing and processing.  I know I want 64 bits version of Windows 7 for my desktop, but would it be OK if I did 32 bits for the laptop? or should I do both in 64 bits?  I plan on having at least 3GB's of memory for each system.

64 bit Windows needs more memory than 32 bit just to run the OS. If you have a laptop with more than 4 GB of memory there is a potential advantage in using the more memory hungry OS to access that memory, but unless you plan to individually mic the Mormon Tabernacle Choir, you can probably get by on less memory and a 32 bit system to address it. I assume you want to use the laptop because you plan to record vocals at different locations than you plan to do your mixing and instrumental recording.

No... that will NOT be an issue. You can easily export the tracks as audio and reopen them in any DAW regardless of the bits on the OS....

The 32/64 bit thing is for the apps, not the audio data.

If it's easier to use 32 on the lappy and 64 on the desk... no problem. I work with people across the net that have 32 and others have 64 bit systems.... I can open their files and they can open mine. We generally just transfer tracks in MP3 and wave..... but I think, if we wanted to spend the time to send the complete Bundle file, we would be able to open those as well across platform.

Just read the last line...XP over W7.

XP has been one of the most stable and rock solid OS's for a DAW.  I understand that the word is that W7 is also very stable BUT..... it is 64 bit. I have it on my desktop biz machine and it's stable.

I understand that you can run in 32bit emulation, but I've heard some have problems doing that. In the full 64 bit mode... of course, the 64 bit apps will run fine. The problem for me, and I'm sure others, is that I have spent quite a bit of money on 32 bit DAW software, 32 bit plug ins, 32 bit synths, 32 bit you name it.... to switch to 64 bit tomorrow, I would need to purchase or at teh very least upgrade everything that I wanted to run in 64 bit.... and for me, that is cost prohibitive right now. My new DAW, and it's processor (i5 750) will run 64 bit and I can upgrade the chip to i7 if I wish to run 64 bit programs a bit faster.  For me, it was cheaper to go with XP. 

Now I also realize that I might be "painting" myself into the proverbial corner going with an almost extinct OS like XP. As long as I don't wake up and decide that I need the new synth that only runs 64bit.... I'll be OK. I have all the original disks and unlock keys, everything is registered...and as long as they make SATA drives, I can clone  my disks and keep on trucking. I am not intending to put this DAW on line...ever... with the exception of unlocking software with the company servers. No upgrades.... no email.... nothing... it is what it is, and I plan to keep it that way.  Long live XP.

If I was getting started today...I would go with W7 and 64bit.... no doubt.

The other problem is I don't think any new laptops will come with XP, driver issues. Its either Vista or W7 now.
I thought there was a W7 32 bit???