Ardens is not a stand alone package it is integral to SystmOne. 

The minimum specification for SystmOne is;

HardwareMinimum Specification
CPUDual core 2Ghz processor or equivalent
Hard Disk Space1GB of free space on the C drive
MonitorA minimum resolution of 1024x720
Memory1GB of usable RAM is required however other applications installed on the devices should also be taken into account because these will increase the amount of memory required for the device to run smoothly
High Memory ClientsSome practices that are sharing more resources than others and perhaps have multiple applications running simultaneously may need to contact TPP to request High Memory Clients are activated for your practice
Connectivity     N3 Internet connection