1* create a folder named "win7" in D drive and copy DVD contents to it (ie: d:\win7\)
2 * download cdimage.exe from
http://create-iso-file.googlecode.com/files/CDIMAGE.EXE
3* copy cdimage.exe to ROOT drive of d:\
4* then use command prompt & change dir to d:\ (just type"d:\")
5* type the following command "cdimage.exe -lWIN7_EN_DVD -m -u2 -bd:\win7\boot\etfsboot.com d:\win7\d: \win7x86.iso"
6* windows windowa7 and vista bootable requires UDF file system & the above command creates the iso image with UDF file system.
7* burn the iso to DVD restart & boot from the DVD
8* 100% working... Tested Already...!!