It is not straight forward to convert a ASP website to a desktop application! Actually you may need to rewrite all of it!
BUT there is a trick you could use...
Instead of rewriting your website you could write a little winform or wpf application that uses the webbrowser control.
Then use a webserver like CassiniDev to run your website locally on the device.
That should do the trick! you get your website running locally on your device inside a desktop application. You can make the UI of your desktop app as complicated as you wish and if you carefully work on your site CSS you could make the site look like if it is a desktop app.
Hope it helps.