how do i boot the iso file using iPXE? for ex i want to boot to hiren.iso

[robinsmidsrod]

You must use the sanboot command to boot the ISO file, and it must be located on a HTTP server. I'm not sure if the Hiren BootCD has been setup to work with network booting, and chances are that it'll have issues to work unless it is based on pure DOS. If you start a windows or linux kernel it will lose access to the CDROM (that is completely normal behavior).

If sanboot is giving you issues you can also try to use memdisk. They provide mostly the same service. The primary difference is that sanboot uses HTTP range-requests to just load what it needs as needed, while memdisk downloads the entire ISO and puts it in memory. Sanboot is also always read-only, while memdisk is read-write. This is usually relevant if you try to sanboot floppies.