Failed to read DHT22 sensor using Intel Galileo Gen2 board
The article link by Nick is the same that I found, so it must be a well search problem.
What is described on the Intel forum is that the Galileo is not capable of direct communication with the sensor as it is a computer and not a microcontroller, so therefore lacks the ability for accurate timing required by the sensor and also the DHT* is considered a peripheral and would thus require a way to interface with the &quot;PC&quot;.
What is described in the post is to use two pins to create the proper digital signal for the DHT.
The circuit makes use of a diode to protect the output pin.
The OP on the forum describes the connections like this:

Pin 2 of Galileo is connected to the data pin of the DHT11.
Cathode of the diode is connected to pin 3 of the Galileo.
Anode of the diode is connected to the DHT11 data pin.

The diode would be a standard diode, possibly a fast switching signal diode as the 1N4143. The resistor would be the standard pull up resistor of 10K Ohms.
Here is the OPs schematic:

(source: intel.com)
You will also need to make use of the code linked to by the OP in the linked post as it was modified to work with the workaround.