After setting the default pxe boot configuration in NBS general the clients still shows only Next Boot Device when boot from network
8.x
unknown
Drill down to path: <install drv>:\Program Files\Altiris\Altiris Agent\Agents\Deployment\SBS
edit the sbsconfiguration.xml file for <> in image, and arch only edit for the client types you require
<sbsconfiguration>
<network>
<interfaces all="yes"/>
</network>
<images rootdir="C:\Program Files\Altiris\Altiris Agent\Agents\Deployment\SBS\Images"/>
<pxe>
<logging filename="SbsLog_Pxe.txt" enabled="no" level="0" backup="yes"/>
<parameters enabled="yes" dhcpdiscoverytype="0"/>
<filters>
<filter parameter="mac" enabled="no" type="exclude" value=""/>
</filters>
<clients>
<client type="managed" enabled="yes" image="<boot configuration>" arch="<arch type>" timeout="3" prompt=""/>
<client type="predefined" enabled="no" image="NextBootDevice" arch="" timeout="0" prompt=""/>
<client type="unknown" enabled="yes" image="<boot configuration>" arch="<arch type>" timeout="3" prompt=""/>
</clients>
</pxe>
<tftp>
<logging filename="SbsLog_Tftp.txt" enabled="no" level="0" backup="yes"/>
<parameters enabled="yes" mtu="1456" maxtransfers="0" tftpport="69"/>
</tftp>
</sbsconfiguration>
After which restart the pxe\mftp services