How to install MS loopback Adapter:

• Open Control Panel, double click 'Add Hardware'
• In the 'Welcome to add hardware' wizard, click 'next', choose 'install the hardware that i manually select from a list(Advanced)' and then 'next'
• In the 'Common Hardware Types' list choose 'Network Adapters' and then 'next'
• Select 'microsoft' in the 'Manufacturer' section and 'microsoft loop back adapter' in the 'Network Adapter' section and then 'next' and 'next'

Open your GNS3 with administrative privilege i.e. right click on it and 'run as administrator'

• Add a router and a cloud or a computer (computer symbol if you have configured its type as cloud)
• Rt. click on cloud/computer symbol, 'configure,' in the 'Node Configurator' window select appropriate cloud in the left column (C0). In the 'NIO Ethernet' tab, 'Generic Ethernet NIO(require administrator access)' select 'MS Loopback Adapter' in the drop down list and click 'Add', Apply, OK.
  
• Now in the GNS3 window, connect router's fastethernet(f0/0) to the computer/cloud's interface which is our loop back interface.
  
• Start the router, console it and enter commands as shown in the below picture.

• Change the speed to 10mbps using 'speed 10' command cos MS loopback adapter network type is 'ethernet' which is 10mbps. Thats how it worked me.

 Now lets go to - Control Panel->Network Sharing center->(left column) Manage Network Connections.

• Rt. click on your MS loop back adapter, select properties.
• Select - internet protocol version 4(TCP/IPv4), and then properties.
• Fill in the details as show in fig.

Verification:

• ping your router ( 10.0.0.1) from windows command prompt.

• ping your loopback adapter ( 10.0.0.2) from GNS3 router.

• OR you also could check mac addresses by 'show arp' in command prompt and router console.

P.S. I "disabled my firewall" totally, this is "Must" OR you could also change your firewall rules to accept ICMP requests instead of disabling it totally.
Making this work wasn't easy but I finally found the solution and it worked, you should be able to get this to work too.