Re: Galileo board is not detected.

mhahn suggested going to the getting started guide, but I think you may have missed that. 

It's likely that it is the "Unknown Device" you see.  Right click on that and update the driver.  For more instructions, follow the Galileo Getting Started guide.  The guide uses an example in which the device is called "Gadget v2.4" in the device manager, however, I've never seen that in my experience and it always comes in as "Unknown Device."  I'll paste that section below.

Step 3 - Install Drivers

1. Windows 7— Install Drivers:
   1. Select Start -> Control Panel->System and Security->Device Manager
2. Locate the Gadget Serial v2.4 device, under the Other devices tree. Right-click that and select Update Driver Software
   2. NOTE: You might get an error regarding a problem installing drivers - you can ignore this error.
3. On the first window that pops up, click Browse my computer for driver software. And on the next page select Browse… and navigate to the Arduino-1.5.3\hardware\arduino\x86\tools folder within your Arduino Galileo software installation. Then click OK.
4. Click Install on the next Windows Security window that pops up. And, after a number of loading-bar-scrolls, the installation should complete and you should be greeted with a Windows has successfully updated your driver software window.
5. Once the driver is successfully installed, Device Manager will show a Galileo (COMx) device under Ports (COM & LPT). Note the COMx port number as it will be needed in the IDE later.