#Grub4dos boot menu install
Check the Don't search floppy option, leave all the other options unchecked and cleared and then click the Install button to install Grub4DOS to the MBR of the flashdrive.
Now click the Part List Refresh button, then the dropdown box and finally select the Whole disk (MBR) option. Once the program is started, select the Disk option, then click the Disk Refresh button and then select your flashdrive from the dropdown box You should be able to tell which disk is your flashdrive by the size shown for each drive. first we need to install the grub4dos into the pendrive.get the grub4dos from following link and unzip to get grubinst_gui.exe and run it.
#Grub4dos boot menu portable
Grub4dos is mainly a boot manager which can be installed in a pen drive or portable hard disk to use as a parallel grub if ur on board grub is down.this can be also used to install certain linux os directly from the iso in the hard disk.This mainly work for ubuntu linux mint and puppy iso's.tthe grub can be also used to log in to the xp and windows 7 if the bootloader is lost.