diff -urN gpxe-1.0.1/src/net/udp/dhcp.c gpxe-1.0.1-xnbauserclass/src/net/udp/dhcp.c
--- gpxe-1.0.1/src/net/udp/dhcp.c	2010-06-29 15:31:33.000000000 -0400
+++ gpxe-1.0.1-xnbauserclass/src/net/udp/dhcp.c	2010-07-29 16:12:58.000000000 -0400
@@ -78,7 +78,7 @@
 	DHCP_CLIENT_ARCHITECTURE, DHCP_ARCH_CLIENT_ARCHITECTURE,
 	DHCP_CLIENT_NDI, DHCP_ARCH_CLIENT_NDI,
 	DHCP_VENDOR_CLASS_ID, DHCP_ARCH_VENDOR_CLASS_ID,
-	DHCP_USER_CLASS_ID, DHCP_STRING ( 'g', 'P', 'X', 'E' ),
+	DHCP_USER_CLASS_ID, DHCP_STRING ( 'x', 'N', 'B', 'A' ),
 	DHCP_PARAMETER_REQUEST_LIST,
 	DHCP_OPTION ( DHCP_SUBNET_MASK, DHCP_ROUTERS, DHCP_DNS_SERVERS,
 		      DHCP_LOG_SERVERS, DHCP_HOST_NAME, DHCP_DOMAIN_NAME,