Eventually I created a new project for something else and found the builder in it worked as expected, so I realized it was project specific. So I compared the .project files and was able to correct the corrupted one using the new one as a reference. Here is an example of how a .project file should look with just the default Java builder:

<?xml version="1.0" encoding="UTF-8"?>
<projectDescription>
	<name>HelloWorld</name>
	<comment></comment>
	<projects>
	</projects>
	<buildSpec>
		<buildCommand>
			<name>org.eclipse.jdt.core.javabuilder</name>
			<arguments>
			</arguments>
		</buildCommand>
	</buildSpec>
	<natures>
		<nature>org.eclipse.jdt.core.javanature</nature>
	</natures>
</projectDescription>

In the above example I have removed my custom builders to focus on the built in one, they would each be listed as extra buildCommand entries in the parent buildSpec node. In my corrupted copy I had several argument and trigger values that were unnecessary. Just for comparison, here is the buildCommand for my custom Windows 7 builder:

<buildCommand>
	<name>org.eclipse.ui.externaltools.ExternalToolBuilder</name>
	<triggers>full,incremental,</triggers>
	<arguments>
		<dictionary>
			<key>LaunchConfigHandle</key>
			<value>&lt;project&gt;/.externalToolBuilders/Win7_Builder.launch</value>
		</dictionary>
	</arguments>
</buildCommand>

Hope this helps someone else out there! And stay tuned, as I’ll be releasing my custom build script very soon for those who may be interested

A Java Runtime Environment (JRE) or Java Development Kit (JDK) must be available in order to run Eclipse. No Java virtual machine was found after searching the following locations:
c:\Program Files\Eclipse\jre\bin\javaw.exe 'javaw.exe' in your current path

I have Java installed, and it is working properly. It was a big pain to get working properly the first time with NetBeans so I was worried that if I tweaked it to work with Eclipse I may end up with it not working in either. I took a peek into many of the config files for Eclipse and didn’t see an option to set the path for javaw.exe, so I made use of my Google-Fu skills and found the following solution:

• Right Click Eclipse.exe and select Create Shortcut
• Right Click the new shortcut and select Properties
• At the end of the target path, add the parameter -vm and then the path to your javaw.exe
  ie: “C:\Program Files\eclipse\eclipse.exe” -vm C:\Java\jdk1.6.0_13\bin
• Hit Ok, then run Eclipse from your new shortcut

Problem solved!