BlackBerry Enterprise Server support for Microsoft Windows Server 2003 Service Pack 2
 

KB13229 - BlackBerry Enterprise Server support for Microsoft Windows Server 2003 Service Pack 2

Microsoft Windows Server 2003 Service Pack 2 is supported in BlackBerry Enterprise Server software version 4.1 Service Pack 4 (4.1.4). Earlier versions of BlackBerry Enterprise Server software do not support it.

-----

That said I've been running 4.0.6, 4.0.7, 4.1.2, and 4.1.3 with no problems.

Patch away new installs!