Windows 7 slow LAN connection RRS feed

  • Question

  • On Nov 1, 2011, I installed a factory-new HP h8t desktop (Windows 7 Professional SP1 pre-installed, Intel i5-2320 CPU, 64bit, 6GB RAM).  It functioned exactly as expected for about 2 days, when I saw a “network cable unplugged” message and lost network connectivity. I was unable to restore my network connection using the integrated Realtek PCIe GBE Family controller. But I had a spare Realtek PCIe GBE controller card on the shelf, which I installed in an empty 2X slot in the computer. I disabled the integrated adapter. This arrangement was trouble-free for several months. However, access to shared files (network shares) has become very slow. Saving a small Word document (50Kb) can take almost a minute. Saving graphics, audio, and video files is a nightmare. In the meantime,my internet connection is about as fast as it always was: 12-13 Mbps. File transfer speeds from all other workstations on our office LAN are acceptably fast.  All workstations connect over a Cat6 LAN to a network switch (Netgear GS724), which ties me to the internet and to local servers (running Windows Server 2003R2) which allow me access to files via network shares, along with eight other workstation on the LAN.  Two other workstations run Windows 7; the others run WinXPSP2. Two Macs are on the LAN as well.

    To recap: the LAN speed problem is severe, and afflicts only the new HP Pavilion h8t.  Every time the HP is rebooted, the network configuration is lost. On re-boot, the adaptor shows “unidentified network” or network cable unplugged”  It can be restored by running “Diagnose” in Control Panel, Network and Sharing, Change Adaptor Settings. Usually I have to run Diagnose twice before it fixes the problem. I’ve already installed the newest driver from Realtek. I disabled TCP autotuning, IPv6, and RDC. I’ve set the adapter Speed and Duplex to auto.  I’ve tried flushing the DNS cache several times. . I’ve tried disabling antivirus. I booted into Safe Mode with Networking. None of these actions has improved the slow network connection. Experiments show that the problem is the same whether copying one large file or many small ones.  Saving and opening files to the local HD is extremely fast. I have no reason to suspect disk drive performance. All  drives in our office, both in local computers and in the servers are 7200 rpm SATA. Since network connection speeds for all other workstations is satisfactory, I can’t help but suspect this one.

    Monday, January 23, 2012 8:47 PM


  • Kind of sounds like a hardware failure of some sort in the computer, since you initially lost connectivity from the embedded controller.  Could it be that you just masked the original problem by trying to install a spare Ethernet controller, and that there are still problems internally?

    Did you run any diagnostics on the computer itself?

    Have you tried running an alternate cable?  Cables sometimes DO have problems.

    What speed are your Ethernet connections?  I didn't see that in the info above.  And are they supposed to be full duplex or half duplex?  I have read that with some controllers the default "auto" configuration doesn't function properly and you have to set the full/half duplex setting for good performance.



    Detailed how-to in my new eBook: Configure The Windows 7 "To Work" Options

    • Proposed as answer by zhen tan Tuesday, January 31, 2012 9:58 AM
    • Marked as answer by Arthur Xie Friday, February 3, 2012 11:57 AM
    Monday, January 23, 2012 9:40 PM