Ok thanks - that's weird because the image I downloaded gave a complete installation menu i.e.You can select this option to use your own installation source from external storage or network. If you want to start your system from DVD and use the same DVD to install the OS you need to use the standard distribution DVD as I mentioned.
I just used the native Windows Disc Image Burner that comes with my Win 7 professional desktophttp://windows.microsoft.com/en-US/windows7/Burn-a-CD-or-DVD-from-an-ISO-file
I even copied the contents of the DVD that was burned and tried a boot from an USB hard drive - got the same messageThat won't work since you cannot copy the hidden boot code.
Hi Jim/everyone who has this problem,
I just want to share my experience and we overcame this issue. Whenever we installed OEL via an iso or DVD the installation went fine, however via network (in our case http) it did not, we got the above mentioned error. After some digging I found the issue was caused by a missing symlink. in the root of the installation folder there is symlink for repodata pointing to Server/repodata. The problem was caused on our side by a Microsoft NAS server which was Fat32 formatted; it does not support softlinks/symlinks. When we tried the installation off my Fedora machine it went fine. Hope this helps anyone who runs into the same issue.