Network / Sharing :: Win 8.1 - No Output Connection But Input Connection Is Normal

I have strange network problem these days. I have a desktop PC and installed Windows 8.1. And I have a LAN. The gateway IP address is 192.168.2.1.

The network works fine when I start the PC. I can access Internet with IE, I can access the config pages of my gateway and I can SSH my local File server. It's a synology ds212j. I assigned static IP address 192.168.2.18 to it and name it as "home_ds". I add dns entry in file "hosts".

But there will be very strange problems if the PC keeps running about 2/3 days. It seems I can't connect to other computers from my PC. No IE, no SSH, no ftp.... But ping still work. These is no network device listed in my network folder. But I still can access the mapped network drives.

For example, I can ping www.google.com, I can ping 192.168.2.1 and 192.168.2.18 and "home_ds".
K:> ping 192.168.2.1Pinging 192.168.2.1 with 32 bytes of data:
Reply from 192.168.2.1: bytes=32 time<1ms TTL=64
Reply from 192.168.2.1: bytes=32 time<1ms TTL=64
Reply from 192.168.2.1: bytes=32 time<1ms TTL=64
Reply from 192.168.2.1: bytes=32 time<1ms TTL=64
Ping statistics for 192.168.2.1:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 13ms, Maximum = 61ms, Average = 32ms

But when I try to telnet and ssh, all failed.

I tried:
telnet www.google.com 80
telnet 192.168.2.1 80
telnet 192.168.2.18 22
all failed.

I tied putty, msn, outlook,... all failed. But my wife's PC works normally at the same time.

In the network folder, there should be a list of all my network devices, including my wife's PC and my File server. But it's empty if this problem happens. However I can add them mannually and I can access the network drives.

And I can connect to my PC from my wife's PC with remote desktop.

If I logout and login again, the network will recover except 1 new problem. That is I can't access the network drives of my File Server with computer name "home_ds", but IP address works. And I can ping it with computer name.

K:>ping home_ds
Pinging home_ds [192.168.2.18] with 32 bytes of data:
Reply from 192.168.2.18: bytes=32 time<1ms TTL=64
Reply from 192.168.2.18: bytes=32 time<1ms TTL=64
Reply from 192.168.2.18: bytes=32 time<1ms TTL=64
Reply from 192.168.2.18: bytes=32 time<1ms TTL=64
Ping statistics for 192.168.2.18:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 11ms, Maximum = 30ms, Average = 19ms

A restart will solve both the above 2 problems. But I don't want to restart my PC so frequently.

I tried to solve this problem by update windows and drivers but failed.