VAS(VirtualAudioStreaming) supports windows server 2003 running in remote virtual machine or VPS.
As to the problem you have:
1) During installation, VAS setup need to generate a virtual sound card on Windows. Windows may pop up warnings, you need to click 'allow install'. See:
http://www.virtualaudiostreaming.net/faq.html2) If you remote control your server, don't use MS remote desktop to configure our virtual sound card driver. Instead, use teamviewer, or pcanyway, or vnc, or any remote control software other than MS's remote desktop When You Configure VAS. You will find there is no error message and Virtual Audio Streaming works perfect with remote control software.
More important, if you like to use MS remote desktop other than
teamviewer, after you finish configuring VAS, you can continue to use MS remote desktop without problem.