Debugger not set in Atmel Studio 6.1

[rj987]

It my first time to try Atmel Studio.
I wanted to try this dev tool before purchase of Arduino Due ARM-based board, so I don't have any hardware yet.
I get error "Debugger not set" when trying to run the first test simple code compile. Under project properties, there is a drop list to select a debugger, but the list is empty, like there is no debugger installed? I had the impression that debug/simulation was fully implemented and included in Atmel Studio, without the need for additional hardware? I can't find any separate install for a debugger? What am I missing?
Thanks for clarification

[rj987]

My project is configured for ATSAM3X8E /Arduino Due ARM based board, not a AVR based board.
After further investigation, the Atmel Studio Simulator documentation shows that Simulator IS NOT supported for SAM3 family of processors The only supported tool is SAM-ICE™ is a JTAG emulator hardware device. (as of 9/6/2013)

When I select any AVR board config for my project, debugger works fine, so this appears to be a lack of support for the newer ARM processors.