Your version of Eclipse is 64-bit, based on the paths and filenames. However, the version of Java that it's picking up is 32-bit, as indicated by where it is coming from, indicated on this line:
-vm C:\Program Files (x86)\Java\jre7\bin\javaw.exe
Program Files (x86) is the folder where 64-bit Windows places 32-bit programs.
Program Files is the folder where 64-bit Windows places 64-bit programs.
This can happen when a system has more than one JVM installed, as is often the case on Windows 64-bit (for example, the JRE download page uses the bit-ness of the browser to determine what bit-ness download to offer you, and many people use(d) 32-bit browsers even though they run 64-bit Windows).
The best way to fix this, assuming you do in fact have 64-bit JRE or JDK on your system, is to specify in eclipse.ini exactly which JVM you want it to use. The instructions are detailed in the Eclipse wiki page, but basically you have to specify the -vm option in the ini file - make sure to read the wiki page carefully as the format is very specific.
Specifying the JVM path in eclipse.ini is strongly recommended because doing so isolates Eclipse from any potential changes to your system PATH that some program installers might make (I'm talking to you, Oracle!).
Another option would be to download and use 32-bit Eclipse instead of 64-bit, but it's still strongly recommended to specify the path to the JVM in eclipse.ini.
Left for historical reference:
To check your version of Java, run
in a console (command prompt). On Windows 7 with 64-bit Java 6 I get:
java version "1.6.0_27"
Java(TM) SE Runtime Environment (build 1.6.0_27-b07)
Java HotSpot(TM) 64-Bit Server VM (build 20.2-b06, mixed mode)
Note the 3rd line, which shows that this is a 64-bit version.
On a 32-bit version you'll get something like:
Java HotSpot(TM) Client VM (build 20.1-b02, mixed mode, sharing)