Backup , But how to Restore - Advice Please

I am still learning , I am looking to make a full backup ( Clone ) of my windows xp , OS, what I would like is if my computer crashes, or has a problem , instead of using the recovery DVD that came with the computer, which only puts back a clean OS, I would like to make a full clone backup to an external HDD, Ive looked at Acronis True Image Home 2009, and can see how to make the clone , but the things I can't get my head around are these ..

( 1 ) I make a full clone image of my Windows XP and put it onto my USB external HDD, if my computer has a problem, how can I restore the clone image from my external HDD to
my computer if the original OS is still on the internal computers HDD

( 2) I make a full clone image of my Windows XP and put it onto my USB external HDD, if my computer
crashes and will not boot up, how can I restore the clone image from my external HDD to
my computer

( 3 ) If my external HDD should also have a problem, could I instead make a full clone to DVD's
if so what's the normal average number of DVD's required to make a full clone ?

( 4 ) To make a full clone backup to an external USB HDD , what size of HDD would you think is the minimum I could use ( have to watch my money )


( 5 ) When ive made the full clone copy, how can I tell that in fact it will restore every thing back as normal when its needed, with out messing up my current working OS .

any advice or comments about making a full clone backup , and restoring back onto a computer
would be most welcome - Thanks

 

Look here at how to create a bootable disk to launch acronis.

http://www.whatsabyte.com/P1/create_cd.htm

Now, are you making a full clone of just your OS drive? or the whole hard drive?

Generally speaking, you should see how much data you have at the time (size) of cloning, then assume that you want at least the same amount of space available on a HDD to clone. I know you can compact/compress the image but compression ratios are not guaranteed.

When you restore, you just restore over your existing data, overwriting it all.

Unfortunately, there is no real way to know without testing/restoring that the image you created is successful.

 

Thanks for your reply, its much appreciated. I really want to make a clone of whole hard drive , its a gamble not to be able in some way to test out the clone, until the day you need it . Just my luck for it not to work .