Can not connect to PC from Android via ES Explorer

I was using ES Explorer to connect to a PC okay but recently I changed the modem then my Android phone can't connect to the computer anymore. I thought it would be caused by a setting on my modem, but searching on Google cannot help me find out. Please tell me how to get my android connected to the PC so I can access files again. Details: I have ES Explorer 3 on Android. My Android is connected to the internet through the same modem as my PC. The D partition has been shared as "Everyone to view. When I add a new server from ES File Explorer, it says "Error, Can not find the server" Update: I have turned off Windows Firewall.