Linux or Windows – for a web Server ??

I have designed a super website, based mostly on Flash applets and I need a professional consult about what should I use as my Server software, the web site clients architecture recommendations are high, because they must have a graphic card with minimum 512 Mb of ram , RAM over 2 GB and 3D support monitor.
The question is which server is going to be better about my website Linux's or Windows Server ?
