Systems Deployment

Hi! Am new to SCCM environment am trying to deploy Windows 7 OS via SCCM 2007 OSD terminology.
Below is my scenario(lab setup using oracle vbox- Extension pack been installed for PXE boot)
Windows server 2008 acting as AD integrated DNS, DHCP, WDS and PXE Service Point all are co-hosted in same server(for lab practice).
Also SCCM 2007 R2,SQL Server 2005 R2 & MDT 2010 are installed all in the same Virtual Machine.

DHCP is working quite fine, i configured PXE service point, WDS role is installed but without configuring the WDS,
services are not getting invoke.so configured WDS Server and configured the DCHP options 60,66,67

In WDS Server enabled(ticked) the options "Do not listen on port 67" & "Configure DHCP option 60 to PXEclient"

executed the wds cmd "wdsutil /set-server /usedhcpports:no /dhcpoption60:yes"

changed the registry key "HKLM\system\currentcontrolset\services\wdsserver\providers\wdspxe usedhcpports to (0)"

At DHCP Server manually included the server options

Server option "066" String Data is updated to "(IP of WDS Server eg:10.0.0.10)"

"067 String Data (\smsboot\x86\wdsnbp.com)"

"060 String Data (PXEClient)"

Ref to this link https://heineborn.co...and-67-for-dhcp

configured the Operating System Deployment--->Boot images--->Operating System Images--->Operating System Install packages--->Task sequence (Create Task sequence using MDT)
Advertised the  Task Sequence to All unknown computer.

When i try to boot the client PC from PXE boot option, it ends with the following errors

Press F12 for network service boot
PXE-M0F:Exiting Intel PXE ROM
FATAL: Could not read from the boot medium! System halted.

Please help me out in resolving this issue.
Thanks in advance.