I don't know if it's said multiple times, but I felt like sharing it.
I've been using WAMP for 2 years now and it's the best AMP-package I've found. Great interface and usability.
BUT I was slightly disappointed about the download speeds I got (max 650 kb/s). I thought it was a cap or something.
Here's how I solved it: By default, 'EnableSendFile' is enabled in the main httpd config. By simply disabling it (unquote the line), it no longer uses the (Linux) optimalisation SendFile which is incompatible with Windows XP / Server 2003.
I don't know if this applies with Windows 7/ Server 2008.