Try uninstalling Web Deploy 2.0. I’ve had IIS and Apache running smoothly for months on a new machine, and suddenly after installing SQL Server 2008 R2 and some Silverlight (yuck) tools to maintain an existing app, Apache reported that port 80 was already taken by “Microsoft HTTPAPI/2.0”. I think it snuck in, along with an unwanted install of IIS 7.5 Express, via the Web Platform Installer. Thanks for stealing 2 hours of my productivity from me, Microsoft. (I don’t get why MS would install that so greedily, and I already had the full version of IIS installed, btw. I hate that Web Platform Installer shit.)
The Web Deploy tool is not something most of us use, in fact I don’t know anybody who uses it at all. So it’s pretty safe to get rid of.