When I try to install DataCore Products on Windows 2003 R2, I get the error message in the attached screen shot. Can DataCore Products be installed on Windows 2003 R2? (Older revisions of DataCore Products will display error messages when installed on Windows 2003 R2.)

All DataCore products may be installed on Windows 2003 Enterprise R2 OS. However, the installer (installshield) in older revisions does not currently recognize the version as valid. As a work around, you must use the regedt utility to modify the O/S version information to reflect something that the installer does recognize as a valid OS. Modifying the registry, if done incorrectly, could disable the computer. If you are unsure, please consult the appropriate Microsoft documentation regarding registry modifications before performing any registry editing.

You need to edit the system registry at: Hkey_local_machine\Software\Microsoft\Windows NT\CurrentVersion and please save off (record) all ProductNames that need to be modifed below before continuing. Then, change the ProductName to equal “Microsoft Windows Server 2003”. Just remove the R2 from the end. Then install the DataCore products and reboot. After the initial reboot, you may then install the latest PSP and any hotfixes as ordinarily instructed. Before the final reboot add the R2 back to the end of the string or restore the string to its original value.

DataCore will be correcting this issue in future releases.

Source: Datacore Knowledgebase