You need to run build with JDK or have tools.jar on the classpath

By default, eclipse will uses the "C:\Program Files\Java\jre7".

Change it, to use "C:\Program Files\Java\jdk1.7.0_xx".

Try setting this to your eclipse.ini file and restarting eclipse to make sure that it's also using your JDK:

-vm
C:\jdk1.7\bin\javaw.exe

Cautions:

• this must go just above -vmargs
• you're full path to your VM maybe different than the one above

See this as reference.