Use External hard drive to boot Windows incase C drive crashes?

Infopackets Reader Steve T. writes:

" Dear Dennis,

I have recently added a 120GB external hard drive to my Dell Dimension computer (via the USB port). Problem: whenever I turn my computer on (to start Windows), the external hard drive always tries to boot first. Inevitably I get an error message that 'operating system is not found' and I have to shut off the external unit and then reboot the machine in order to start Windows properly.

For this reason, I am curious if my Windows XP crashes, would it be able to boot from the external hard drive? If so, how would I go about doing this? Right now I'm just using the external hard drive to backup my most important files (but only when Windows is loaded). If Windows wasn't loaded, I wouldn't be able to use the drive. "

My response:

Yes, it is possible to use the external hard drive as a total replacement / backup unit if your internal C drive crashed and you were no longer able to boot into Windows. This is called making a mirror image of your hard drive.

You can do this if:

a) your external hard drive is as big or bigger than your internal hard drive, and

b) you use a disk imager like Acronis True Image to make a "mirror copy" or "disk copy" from the internal hard drive (C drive) to the external USB drive (D drive, for example). A mirror copy essentially copies the *entire* drive from one to the next.

Also very important:

Based on your statement, you will need to modify your boot sequence so that your external hard drive does not always try to boot first. Otherwise, you will be booting off your external hard drive after your first mirror copy is completed. This is not what you want, because any changes to the system will be done to your backup drive instead of your internal PC hard drive.

You can change your boot sequence by going into your computer's BIOS (Basic Input Output System). On most computers, the BIOS can be activated by holding down either the DEL or the F2 key when you first turn your computer on. Normally there is a message displayed at the bottom (or top) of the screen to "Press XXX key to enter CMOS / System Utility", etc.

Once you're in the BIOS, look for a section that pertains to "Boot" or "Startup". Since not all BIOS's are the same, I can't give you explicit directions where to look, although on most Dell PC's it's the last menu option on the top right of the screen.

When you're in the Boot menu, ensure that the C drive boots first, then the CD/DVD ROM, and then the USB drive (note that your external USB drive will need to be plugged in and turned on in order for it to show up in the list of bootable options). For the Dell PCs, you can adjust the boot sequence in a hierarchy by moving the cursor over top of an item and then by pressing the + or - key.

Good luck.

PS: The Review on Acronis True Image, if you haven't already read it, is online our site. I highly (highly!) recommended True Image if you want piece of mind incase your system ever becomes unbootable or you get hit with a virus or Spyware attack, etc. I personally use Acronis and wholeheartedly recommend it to friends, family, and everyone who reads this newsletter.

Acronis True Image Review