Hi Sadam,
Thanks for your interest in the SDK. The ArtemisDotNetSDK is no longer supported and has now been removed from the core installer. However, you can download the latest SDK from the downloads page:
http://www.atik-cameras.com/downloads/ (Bottom of page)
The SDK doesn't contain any .NET components yet, but you can easily PInvoke any methods you need. I can also supply some .cs wrapper files on request (essentially the files I use for infinity).
Please make sure you read through the documentation. In particular the 'ArtemisHSC.dll Guide' as this will guide you through all the steps you need to get set up. There is also an example application (written in c++) which should help get you started.
If you have any problems, feel free to email me at ChrisG@atik-cameras.com
Chris.