We have a PXE server that will not successfully pass down the bootstrap (Bstrap.0) file to our clients. When clients PXE boot, they get either error "PXE-E74 No MAN_INFO or OS_INFO options found" or "PXE-M0F: Exiting Intel Boot Agent".
Review DHCP Scope Options as if previously PXE was configured in Forced Mode - configuration might be pointing to old IP. You can use PXE Forced Mode Utility from KB 28035. (Linked Article).
Another case that showed this issue was resolved by uninstalling the PXE server completely (leaving only the mmaccesskey.ini file in the PXE directory), reinstalling the PXE server and creating new PXE boot images.
Deployment Solution 6.9 SP1 (MP1 added also)
Using PXE Forced Mode