Upgrading Windows NT/2000 to Windows 2003 (Part 1)

Please Note:
Ensure that you have the passwords to administrator accounts and to the active directory restore account passwords. 

Note: 
If you are considering an upgrade make a recoverable backup in all circumstances, this will prove useful if you need to back track to the previously installed Operating System. An easy way to do this is to mirror the hard drive to an alternate hard disk and then use the new alternate disk for the upgrade. In the event of the upgrade not working you can easily fall back to the original configuration. If for some reason it is decided that a roll back position is not needed you may want to verify that your current Operating System can be upgraded and that the applications installed on the operating system are supported by the new installation. This can be done by installing a product like Virtual PC and then installing the current Operating System and then upgrading to the newer Operating System this method closely mimics what would have happened on a traditional installation. When upgrading takes place data files are not destroyed or overwritten, however if the data is important you should be backing it up. Backup every thing you want to keep. Before upgrading it is always a good idea to go thorough the event log, the logs may point to problems that may already be affecting the system attempting to fix them before the upgrade and after your backup may be beneficial. Before starting an upgrade it is recommended that the latest service packs and Windows updates have been applied.

Before upgrading you need to ensure that:

1. You are part of the Schema, Domain or Enterprise Admins Group.
   
2. The ADprep util is used, that comes with Service Pack 1 for Windows 2003, this will help you when upgrading the OS, the utility has better reporting mechanisms that help the upgrade go more smoothly and it highlights incompatibilities that may be present.
   
3. If running Windows 2000 the Administration tool pack must be removed before upgrading to Windows 2003.
   
4. If you are running services for Unix version 2.0 upgrade to Services for Unix version 3.0
   
5. If you are running Exchange on your windows 2000 domain you need to run the LDF on the Windows 2003 CD called Exchangefix.ldf. You can use this with LDIFDE. This will fix the schema errors that were formed by the Exchange 2000 FORESTPREP. After this tool has run successfully you then will need to run FORESTPREP for Windows 2003.
   
6. Ensure that DNS is working correctly and that other servers can be reached using their name.
   
7. If SBS 2000 is installed the upgrade path is only available if the upgrade is done to SBS 2003.
   
8. When installing or upgrading to Windows 2003 ensure that the disk that you are installing to is not compressed unless compressed using Windows NTFS. My recommendation is not to install on any drive that is compressed.

Upgrading to Windows 2003, its functional levels and Migrations Paths

When a new Microsoft operating system is designed the legacy client’s compatibility issues are always considered. Legacy to Windows Server 2003 would include Windows NT 4.0 and Windows 2000 Domain environments. A rule of thumb is to know that the functional level chosen typically states what type of functionality the Operating System is operating under.

It has to do with functionality!

There is a lot of new functionality within the Windows Server 2003 environment. The challenge is a lot of this new functionality is dependant on all Domain Controllers in the Active Directory Forest running Windows Server 2003. 

The functional levels available are:

The table below outlines the Functional levels Domain Wide and Forest Wide and their features.

Domain Wide Functional levels

Forest Wide Functional Levels

1. When installing Windows Server 2003 and promoting the server to a Domain Controller. after installation there will be 3 Functional levels available, respectively Windows 2000 mixed mode Functional Level, Windows 2000 native mode Functional level and Windows 2003 Domain Functional level.
   
2. After an in place upgrade (upgrading over current Windows installation) from Windows NT 4.0 to Windows 2003. The Domain controller could be in the Interim Functional Level or mixed mode functional level based in this Scenario.
   
3. If the Domain controller is running Windows 2000 and is in Native mode, after the upgrade, the Domain Controller will be in the Native mode Domain Functional level and will have Windows 2003 Domain Functional level available to it.

Note:
When upgrading or installing Windows 2003 it is recommended that UPS equipment communication cables be disconnected as it sometime interrupts the device detection process. This also applies to other non-standard devices that may be attached to the server.

1. Step one: Locate the Domain Controller (DC) that is the Schema Master. This will be the DC server that holds the Schema Operations Master Role in Active Directory. This server writes operations to the directory schema responsible for update replication to the schema partition, destined to other domain controllers in the forest. At any time, the schema master role can be assigned to only one domain controller in the forest root domain.
   
2. Step two: Locate the server that is the Infrastructure Master. The Infrastructure Master is a DC that holds the Infrastructure Operations Master Role in Active Directory. It is responsible for cross domain references of security groups. This DC updates the group information that maps the location of the user in a group, this DC then replicates the change to the domain. It is possible to find both the Schema and the Infrastructure Master on the same DC.
   
3. Step three: These servers are critical and before an upgrade is performed a full backup should take place of both computers.
   
4. Step four: Disable the LAN connection on the Schema Master DC until instructed to reconnect. While DC is disconnected you may find replication errors in the event log because of this. These errors will disappear once the server is reconnected.
   
5. Step five: (Schema Master), insert Windows 2003 CD while the Windows 2000 OS is running, then open the command prompt >start run cmd ;).  In the I386 directory on the CD you must run the adprep /forestprep command. Note this command must run uninterrupted and must succeed to move to the next step.
   Quick tip:
   On any DC you can run the DCdiag (domain controller diagnostics tool) to test and find out information about the domain controller.
   
6. Step six: (Schema Master), look in event viewer for problems that could have occurred during the upgrade. If the adprep /forestprep command failed it typically displays instructions on what to do next to resolve the problem. You may need to restore from backup to resolve the problem. If all went well you can now double click the disabled NIC network interface card you disabled in step four to reconnect the Schema master DC back to the network.
   Note: 
   Assuming the Schema and the infrastructure master are on separate DC’s the changes must replicated from the Schema to the Infrastructure Master this should take 10 minutes but it is a good idea to leave it for a while longer to make sure the replication takes place especially if there are WAN links between sites. Run ADprep to ensure that the replication has taken place.  If the forestprep is not replicated to all DC’s in the AD forest the domainprep will not run.
   
7. Step seven: (On all Infrastructure Master Computers), insert Windows 2003 CD while the 2000 OS is running, then open the command prompt >start run cmd ;).  In the I386 directory on the CD you must run the adprep /domainprep command.
   
8. Step eight: (Infrastructure Master), look in event viewer for problems that could have occurred during the upgrade. If the adprep /doaminprep command failed it typically displays instructions on what to do next to resolve the problem. You may need to restore from backup to resolve the problem.
   
9. Step nine: You will now be able to run the upgrade or leave the computers like this till you are ready.
   
10. Step ten: As an administrator in the I386 directory on the Windows 2003 CD run Winnt.exe and follow the prompts.

Summary

In this article we covered parts of the upgrade process that need to be considered when upgrading to Windows 2003, Active Directory is a complex repository that needs preparation during the upgrade process this will be covered in Part 2 of this article.

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