For starters this is still a new science and many people have had good luck with at least one of these methods and others have not. Note that flash drives are often also called thumb drives, keychain drives, pendrives, etc.
A FEW THINGS YOU NEED TO CONSIDER IN ADVANCE. 1. The PC has to support booting from a USB flash drive. There may be anywhere from 1-3 items to change in the BIOS to make this possible assuming your BIOS supports it. Some bios's may refer to your flash drive as a USB floppy or USB zip.
2. The USB flash drive must support booting from it in general.
3. The flash drive must contain the boot/system files.
4. The flash drive must have bootsector area. This is done with special utilities.
5. References to "A:" drive lines in the autoexec.bat and/or config.sys files you copy to the drive after you make it bootable may result in errors.
6. You "may" have to format your floppy disk first in WinXP before you create a bootdisk as XP may "not" like working later on with a disk formatted otherwise.
7. Included below is a bootable ISO of DOS 7.1 which may be used with some of these methods if you do not have a 1.44 drive.
METHODS Method 1 - Make your flash drive bootable using Bart's mkbt util: http://www.nu2.nu/mkbt/ -- Alt: mkbt20.zip
Put a bootable floppy disk in your A: drive or create one using Windows.
Download mkbt20.zip and unpack to to new temp folder you create.
Go to the temp folder.
Extract the bootsector from the bootable floppy disk. eg Open a DOS Window and go to the directory where you extracted MKBT. Type:
mkbt -c a: bootsect.bin
The boot sectors from the bootable floppy disk have just been saved to a file in the temp folder you created.
Format the flash drive in FAT or FAT16.
Copy the bootsector to the flash drive. Open a DOS Window and go to the folder where you extracted MKBT. Type:
mkbt -x bootsect.bin Z:
"Z" represents the flash drive drive Letter. So if your flash drive has another drive letter, then change the "Z" accordingly.
Now you can [grin] "should" be able to copy the utils you need to the pen drive.