Upgrade from Windows 2003 R2 32 bits to 64 bits


I would like to upgrade all my servers (5 members servers) and 1 domain controller from Windows 2003 32 bits R2 to Windows 2003 64 bits. How do i go about it? The hardware spec is able to support 64 bits.

Should i upgrade the DC first follow by the rest of the members servers?

If it is the DC, what other things should i take note?
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Krzysztof PytkoSenior Active Directory EngineerCommented:
You can do that separately, DC doesn't have to be upgraded first but it's recommended to start from it.

You need to have new hardware because in-place cross-platform upgrade is not supported. You cannot upgrade 32bit OS to 64bit at all, you have to reinstall server. Besides, that's better option that doing an in-place upgrade. You will have clean installation without mess from previous OS.

How to add the first 2008R2 Domain Controller in 2003 network, you will find on my blog at

after that, you may wish to transfer FSMO roles to the new DC

when you transfer PDC Emulator role then you need to advertise new time server in your forest

[...]- after transfer of the PDCEmulator role, configure the NEW PDCEmulator to an external timesource and reconfigure the old PDCEmulator to use the domainhierarchie now. Therefore run on the NEW "w32tm /config /manualpeerlist:PEERS /syncfromflags:manual /reliable:yes /update" where PEERS will be filled with the ip address or server(time.windows.com) and on the OLD one run "w32tm /config /syncfromflags:domhier /reliable:no /update" and stop/start the time service on the old one. All commands run in an elevated command prompt without the quotes. [...]

an extract from MVP blog at

Make sure that you have redundancy for Domain Controllers, adding another one

when you are sure that everything is set up properly and DCs replicated AD data, you can decommission the old one

The rest servers you need to reinstall separately. Do data backup and then restore on the new system (before that, check if all application used by you are compatible with 2008R2)


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DecarnAuthor Commented:
Hi, as this environment is purely a development one and hence there is not much resources for new hardware that i can "play" with. I understand that there is no way to upgrade from 32 bits to 64 bits other than total new installation of the 64 bits OS.
So in the case, would it be better that i upgrade the members servers first? and PDC would be the last one? I had only one domain controller and there is no bdc.
By the way, i am just upgrading from 32 bits windows 2003 to 64 bits windows 2003. Thanks.
Krzysztof PytkoSenior Active Directory EngineerCommented:
Oh 2003 to 2003 :) I thought that from 2003 32bit to 2008R2, sorry ;)

In this case I would leave DC untouched. There is no sense to change 2003 32bit DC to 64bit if there is no more than 4 GB RAM and you will not see any improvement

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DecarnAuthor Commented:
oh because some of the development applications are hosting on the DC and we would want to simulate the same environment as in our production servers and hence we will need to upgrade to 64 bits. Your advice please. thanks
You will need to promote a different server to be a DC, at least temporarily while you wipe and reload your current DC. The order that you upgrade doesn't matter much since everything is compatible. It is a fair amount of work because you have to rebuild everything other than Active Directory.
DecarnAuthor Commented:
promote different server to be a DC? as in to seize the roles from the current DC?

I was thinking to upgrade all the existing member servers to Windows 2003 64 bits first and lastly would be the DC.

Any guides on upgrading the DC to 64 bits or as in to promote a different server to be a DC
You only sieze FMSo roles if the original server isn't available. You need to always have at least 1 DC at all times. If you upgrade your DC last, who will be the DC when you wipe and reload the DC? Take one of your member servers (32 or 64 bit), run dcpromo on that member server to make it a DC. Make sure that it has DNS and is a global catalog server. Transfer all FMSO roles to it. You can then demote your original DC, reload Windows on it, and join it to the domain. You can either then use it as a member server, or run dcpromo on it to make it a DC with global catalog and DNS. You then have the option of demoting the other DC or leave it as is.
Krzysztof PytkoSenior Active Directory EngineerCommented:
Yes, I agree with Kevin. Follow his advices and you will be good.
Remember that Windows Server 2003 durin promotion doesn't make DC a Global Catalog and do not install DNS role itself. You need to do that after you promoted new DC in your network (if you need assistance, just let us know).

After that you can simply transfer FSMO roles because your previous DC is still available and install there those apps (however, I would not recommend using DC as Application server, just only DC/DNS/DHCP - for security reason)

DecarnAuthor Commented:
thanks to the both of u.

So in general, i would just upgrade all the members servers first to Windows 2003 64 bits. Then i will promote one of the member servers to the DC (and hence there will be 2 primary DCs?)

After which, then i will use the new DC to seize the FSMO role from the old DC and after which i will demote the old DC? and proceed to upgrade the old DC to 64 bits. When it is done, will seize the FSMO role back and promote the old DC back?
Krzysztof PytkoSenior Active Directory EngineerCommented:
There are no PDC/BDC these days :) All of them work in multi-master replication topology and have read/write AD database, so the only one of them holds FSMO roles, that's teh difference.

And yes, upgrade your member servers then install temporary DC and transfer FSMO roles to it. Make it also DNS server and Global Catalog. Wait for replication and then decommission the old 32bit. Reinstall OS to 64bit and promote it as DC again with DNS and Global Catalog also. Transfer back all FSMO roles to the "previous" DC (do not seize FSMO roles, it's not needed, all DCs are available all the time, so the only thing you have to do is transfer them using GUI or command-line). Wait for replication is being done and decommission that temporary DC (but I also suggest like Kevin to have at least 2 DCs for redundancy)

And that's all :)

I think you have it generally correct, but you are using terms that mean different things than what you want to be doing. You don't sieze the FSMO roles, you only want transfer them.  Siezing is for when the DC with the FSMO role is offline and can not be ever brought back online.

There are no primary domain controllers anymore. There are only domain controllers, and read-only domain controllers in Windows 2008 environments.

Of course, you will need to promote the old DC back to be a DC before you can transfer the FSMO roles back to it.
I didn't mean to duplicate Krzysztof, it just takes me a little while to type up my posts.
Krzysztof PytkoSenior Active Directory EngineerCommented:
Don't worry Kevin :) For now, Decarn can be sure for those steps :)

DecarnAuthor Commented:
really thanks for all your advice. Would try it out and get back to you all if i face any problems.

My database would like to be clustered but i am not too sure how to go about it.. will create a new thread on clustering. thanks
DecarnAuthor Commented:
hi all, i have two VMs where i simulate the upgrading of 32 bits server to 64 bits before i perform the actual upgrading.

My DC is Windows 2003 32 bits whereas the other member server is 64 bits. When i do a dcpromo on the member server, it hit an error saying "The operation failed. The version of the Active Directory schema of the source forest is not compatible with the version of Active Directory on this computer"

I was wondering it could be because of the difference between 32 bits and 64 bits.

How do i tackle this problem? thanks
I would only expect that when trying to promote a server that is running a newer version of Windows than the current DCs. Maybe the existing DCs are Windows 2003, and your new server is 2003 R2?

try running adprep /forestprep, and then adprep /domainprep from the current schema master. adprep can be found on the Windows 2003 installation CD.
DecarnAuthor Commented:
hi kevin,

The 2 VMs that i had one is running Windows Server 2003 R2 Std 64 bits and the other is running Windows Server 2003 Std 32 bits. Guess is the R2 version. Will try running adprep /forestprep and adprep /domainprep on the Windows Server 2003 Std 32 bits.
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Windows Server 2003

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