DUAL BOOT- How to install second copy of Windows 8 X64

I have ASUS laptop which came with pre-installed Windows 8.1 X64.

When I try to install a second copy of Windows 8.1 X64. I get the following message

“ windows can not be installed to this disk. The selected disk is of the GPT partition style”

I found suggestions at


#1 - How to "Clean" or "Clean All" a Disk with the Diskpart Command
http://www.sevenforums.com/tutorials...t-command.html

#2 - ANOTHER TUTORIAL



Before I use these suggestions I would like to know

1.“clean” command of Diskpart will mark data on the HDD as being deleted. How do I recover my original Windows 8.1?

2. Does this command change GPT partition style to something else?

3. I have 2 HDD,
Disk 0- empty (1 TB)
Disk 1- OS and recovery partition etc (1TB)
Can I use clean command on Disk 0 (which is empty) . Will mix and match work?

4. Can I have more than 1 boot partition on GPT partition type?

I do not want to change Disk 1 due to my service warranty conditions.

Hope someone can help me.

Thank you very much.