I dont want it to replace my Windows 7 that is currently installed.... so is there any way of doing this?
Correct. You don't want to give up your Win7 install while you test the Win8 Preview (it's still pre-beta OS after all).
You can run Win8 in a VM (virtual machine) or install it as a dual boot option - Win7/Win8 choice at bootup. How to Dual-Boot Windows 7 and Windows 8 Side By Side