I want to boot from usb flash drive. how can i do ?

You might want to boot from a USB device, like an external hard drive or a flash drive, for many different reasons.
When you boot from a USB device, what you're actually doing is running your computer with the operating system that's installed on the USB device. When you start your computer normally, you're running with the operating system installed on your hard drive - Windows, Linux, etc.

How To Boot From a USB Device
Change the BIOS boot order so the USB device option is listed first. The BIOS is rarely setup this way by default.
If the USB boot option is not first in the boot order, your PC will start "normally" (i.e. boot from your hard drive) without even looking at any boot information that might be on your USB device.
Tip: The BIOS on most computers list the USB boot option as USB or Removable Devices but some confusingly list it as a Hard Drive option, so be sure to dig around if you're having trouble finding the right one to choose.
Note: After setting your USB device as the first boot device, your computer will check it for boot information each time your PC starts. Leaving your computer configured this way shouldn't cause problems unless you plan on leaving the bootable USB device attached all the time.
Attach the USB device to your computer via any available USB port.
Note: Creating a bootable flash drive or configuring an external hard drive as bootable is a task in itself. Chances are you made it to my instructions here because you know whatever USB device you have should be bootable after properly configuring BIOS.

• Restart your computer.
• Watch for a Press any key to boot from external device... message.
• On some bootable devices, you may be prompted with a message to press a key before the computer will boot to the flash drive or other USB device.
• If you do nothing, your computer will check for boot information on the next boot device in the list in BIOS (see Step 1) which will probably be your hard drive.

Note: Most of the time when trying to boot to a USB device there is no key-press prompt. The USB boot process usually starts immediately.

• Your computer should now boot from the flash drive or USB based external hard drive.

1. The PC has to support booting from a USB flash/pen/key drive. There may be anywhere from 0-3 items to change in the BIOS to make this possible assuming your BIOS supports it. Some older 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. There are several programs available if you do a Google search that will help you make your USB Flash Drive bootable as well.

Go into BIOS by pressing correct F key that is noted during boot. Make USB drive 1rst boot, save and exit.

The USB installation also needs to be bootable and made so with software like Novicorp

If you change the Boot Device startup order with the USB port as the first boot device then you can boot up with an USB hard drive or USB Flash device.

use window 7 installation bootable disc. that will help...

You have not specified your operating system. However I will explain how to do it with windows 7. First you have to create a bootable flash drive. Do it as follows
Format USB flash drive to NTFS format(For Win XP only. Vista users can directly format the USB drive to NTFS format) In your Windows, go to Control panel -> system -> hardware -> Device manager.
Under the disk drives section, right click on the USB storage drive and select Properties.
Go to the Policies tab, select optimize for performance. Click OK.
Open your Windows Explorer, you should see the USB storage drive in the inventory. Right click and select Format. Select NTFS from the drop down bar. Click Start.
For Windows XP,
Download MBRWizard. Extract the zipped files to your desktop.
Open a command prompt (Start -> Program -> Accessories -> Command Prompt).

cd Desktop/MBRWiz2.0/
MBRWiz /list
Record the USB flash drive disk number
Make the USB drive active.

mbrwiz /disk=X /active=1
For Windows Vista,
On the Start menu, navigate to the command prompt entry. Right-click and select Run as administrator.
Type

diskpart
list disk
Record the disk number of your USB flash drive.
Select the USB disk.

select disk X (X is the drive number of the USB flash drive)
List the current partition. Record the partition number.

list partition
Select the current partition and make it active.

select partition Y (Y is the partition number of the USB flash drive)
active
Creating bootable USB flash driveDownload Windows 7 iso (32-bit) file to your desktop (The download link is no longer valid).
Download and install WinRAR.
Right-click on the Windows 7 iso file and select Extract files. Extract the files to a folder (you can name the folder any name you want, but for illustration purpose, I name it win-7) in your desktop.
In your command prompt, cd to the windows 7 folder.

cd Desktop/win-7 (Change the destination to the folder that you have extracted)
cd boot
bootsect /nt60 X: (X is the drive latter of your USB drive )
Now, copy all the files from the Windows 7 folder to the USB flash drive.
Reboot the computer. Remember to change the first boot device to your USB drive in the BIOS.
You should be able to install Windows 7 from your USB flash drive now.

Generally, you need a few things:

1. The PC has to support booting from a USB flash/pen/key drive. There may be anywhere from 1-3 items to change in the BIOS settings 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. Of course there are exceptions.
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.

Check out this comprehensive link to make a bootable USB / flash drive in your choice of several different Operating Systems.

I hope this helps and good luck. Please rate my reply. Thank you!

When u just turn on your laptop go to bios settings.....in bios settings change the boot priority to USB flashdrive....save and restart before you restart connect your flash drive to ur laptop......it will ask boot from flash drive press any key....n contiune...hope this helps

Hello,

I don't think this is possible. Still we can work on this.

Even I am verymuch Intersted with these kind of issues. I haven't tried installing XP on USB flash drive. But I installed the XP on USB harddrive and it worked.

We can try this with your co-operation. To boot with the USB devices, first your computer or laptop should have the option to boot with the USB devices. You can check in BIOS, under BOOT order for this option.

If USB boot option is not there, then you cannot boot with the Flash drive, not only flash drive all USB devices. They will work only after booting into Windows.

Comming to installation procedure, installtion is same as installing the XP on harddrive. While installing the XP, at partition page, you can see the USB flash drive, select it and continue the installtion.

If your computer has the option to boot with the USB devices and if the flash drive won't boot into Windows after installtion, then we have to set Flash drive as Active partition from Disk Management, and then we can try. In Disk Management, right click on the USB drive and select set active partition. If it won't allow to set the USb flash drive as active, then it is not possible to install XP on flash drive.

Even I googled everywhere on how to do this, but not information.
Try that and let me know the status. But I am sure, it is possible on Pocket drivers or USB harddrives.