Will installing ML to a 2nd HDD mess up current install?

[bitterdone]

I want to install ML onto a spare HDD. If I create a bootable usb installer, tell my iMac to boot from it, and install ML to the HDD, will anything bad happen to the iMac's current OS X installation?

I'd be using a usb HDD Dock ("toaster") to connect my spare HDD. I think the iMac has Snow Leopard, if it matters.

 

[simsaladimbamba]

It will not damage the current install if you select and format the correct HDD during the installation.

 

[bitterdone]

Thanks for the response. To you and anyone else wondering, I just finished and the original install is fine.