Minimum RAM recommendation for Windows Server 2003 R2 Standard x64

4GB is the max RAM for your hardware:
http://h18000.www1.hp.com/products/quickspecs/11614_div/11614_div.html

Comparison of Server 2k3 versions:
http://technet.microsoft.com/en-us/library/cc758523%28WS.10%29.aspx

How many users are in your environment? Would this be the only DC and print server?

Probably adequate but not speedy.
I have a 2003 DC 32 bit with 3Gb and a 2003 32bit file server with 4GB for about six years now.  Printserver/Users directories for 100+ users is 2003 32 bit with 2GB
My ERP server is 2008 64bit with 6GB and 20 users

It would be excessive for a DC in all but the largest environments.  And it would be excessive for a file and print server in all but the largest environments.  1 GB should be more than enough.  You need RAM for RAM intensive apps - Active Directory (except if you have THOUSANDS) of users is not a RAM intensive function and neither is File and print serving.  Print maybe a little more than file, but unless you are holding 200 printers and each are being printed to CONSTANTLY, it's not necessary to have a lot of RAM.

Put another way, I used to support 1000+ users on a file/print server with 512 MB of RAM and 150 printers.  We also had 3 DCs, each with well under 1 GB of RAM.  That WAS 2000 Server, but there weren't that many changes between 2000 and 2003 (and the fact that you're using 64 bit instead of 32 bit doesn't impact that in any meaningful way - in general, all 64 bit means is that you can easily exceed 4 GB of RAM... not that you need x MB/GB more.

Keep DC and File server on different server. MS recommends minimum 2GB RAM for DC servers.

> MS recommends minimum 2GB RAM for DC servers.
Please cite your source for a 2003 server; I believe this may be true when running 2008 or 2008 R2, but not for 2003.

Hi

Thanks for all the speedy replies..

I should have stated, these are 2 seperate ML330's,  one is a file and print, the other is a DC.

They are going to field locations 2 in each site.

We want to use 64 bit O/S's not 32 bit seeing as the ML330's are more than capable of handling this.  
Or do we need to??

I also should have mentioned the ML330's are G6 models and not G3.  The maximum memory these boxes can handle is 192GB!!

Leaving for the day but will check tomorrow
Thanks again

@amitkulshrestha,

Thanks for posting the link.

As the link states the MINIMUM is 512 MB, but that does depend on the number of users.  Logically, to me, if his environment had 1000's of users, they would be employing experts sufficiently knowledgeable to know this already.  I certainly would fear for the company that was that big but didn't know resource utilization for common functions.  A person asking that question here is probably more of a jack of all trades and/or someone just forced into IT because they know the most of anyone currently employed by the company, meaning the number of users will definitely be lower than 500.  Of course, I could be wrong, but given logic and probability, I'm comfortable saying that 1 GB (or less) is likely JUST FINE for his environment.

Thanks for suggestion Leew. I too agree with you.