Vista Business Complete PC Backup Question

I know the following question is kind of silly but asking never hurts...
(at least so they say :zip.

I tried to do a complete PC backup using Windows build in "Back up
Computer".

The next screen that pops is the one where I have to select the drive I
want to save the backup image.

-So my question is the following:-

If I choose to save that backup image that Windows is about to create
to my second partition (The same physical drive the boot/system
partition is - I know its not recommended), will I loose any data that
is already on that partition?

Like i said, I know it's a silly one but I was just wondering since the
wizard only gives me the option to select the drive and not a specific
location I want to save it in.

Thanks in advance,
jimmy.


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jimSON