My Windows 7 Starter works fine with USB DAC. No driver problem anymore.
I downloaded a driver installation program USB-108-091014-7.12.8.2140(W7-LO-01).rar from
http://www.audiophileproducts.com/fubar4plus
and Free RAR Extract Frog 2.50 from
http://download.cnet.com/Free-RAR-Extract-Frog/3010-2250_4-11661271.html
to uncompres the .rar.
After running setup.exe my Cambridge Audio Dacmaxic started to work, Lehmanaudio Rhinelander headphone amplifier amplified the signal to my AGK 701 headphones.
The Spotify premium content is now a pleasure to listen to using my Samsung NF320 netbook.
I believe this solution will also work for Windows 7 home premium and for Nuforce Icon HDP to solve the irritating driver problem.
Markku P