Microsoft ISA Server 2004 Standard Edition is designed to run on servers with up to four processors (when licensed individually). However, when installed on a multi-processor computer, ISA Server 2004 Standard Edition incorrectly counts hyper-threaded processors (e.g., Intel Pentium IV), causing the ISACTRL and WSPSRV services to not start if more than two such processors are present. The ISA Server Control Service incorrectly views each HT-enabled processor as two processors, and perceives the installation as being in violation of the licensing terms as ISA Server 2004 Standard Edition is limited to a maximum of four processors.
HT processors should be counted as a single processor, such that servers with up to four HT-enabled processors are fully supported and viewed as being compliant with the products licensing. Servers with only one or two HT-enabled processors or servers running on older non-HT processors are not affected by this bug. Servers with three or four HT-enabled processors should be updated with this patch, and will load normally after installation and reboot. This version is the first release on CNET Download.com.