I created an ASP.NET WEB project in VS2012 and add a WCF Data Service file(.svc).When i run, i can reach it(localhost:61388/default.svc), but i can't reach it in another computer by typing my host's ip address(192.168.1.4:61388/default.svc) and it shows BAD REQUEST-INVALID HOST NAME. Then how can I reach my wcf data service from another computer? I've turned off all firewalls and my os is windows 7 Pro
For that you need to host your WCF service in IIS server...To learn more about IIS server and add website see this
BY default there is a default website running at port 80.(You can check by typing http:\localhost) If you dont get anything that means IIS is not installed in your PC.
Once your IIS is up and running add your WCF service to IIS just like you add website to IIS (Or directly publish your WCF service in IIS publish-->IIS) and give it a specific port number (lets say your WCF service is running at 81).you can access the service from other computer (Lets say the PC which host has ip 10.20.50.121)...then you can access it on another computer by typing 10.20.50.121:81.
Now to connect your WCF service to Website,you need to check if your wcf service is running or not.For that when you publish your wcf service to IIS you get 3 files out of which one is default.svc(or any of your name you can click on the service go to contents view and see it) click it and on the right hand side click browse if you see a success page that your service is running then you need to copy that address an paste it in your Website webconfig endpoint address location and change the appopriate dns value .That should get your WCF service started