Serial communication very slow RRS feed

  • Question

  • I have a VB.net program running under Windows 7 which handles communication between a PC and various independent devices using, among others, serial ports with a GSM modem attached. On my Windows 7 professional PC (x64) this serial communication is up to 10 times slower than under WinXP SP3. Does anybody have any idea what can be the cause for this behavior and how to fix it?

    Any help will be appreciated.

    Thanks in advance,


    Saturday, August 14, 2010 10:13 AM


  • Hi Helmut,


    Is the program originally written for Windows XP? Ensure that the program is compatible with Windows 7, you can try running the program in Windows XP Compatibility Mode or in Windows XP mode to see if the performance gets better.


    How to run programs in Windows XP Compatibility Mode



    1)    Right click on the exe file for driver and click Properties.

    2)    Click on the Compatibility tab.

    3)    Select “Run this program in compatibility mode for.”

    4)    Choose Windows XP (Service Pack 3)/Windows Vista (Service Pack 2) from the drop down list.

    5)    Select “Run this program as an administrator” option under the Privilege Level topic.

    6)    Click Apply, click OK.

    7)    Please double click on the exe file again.


    Install and use Windows XP Mode in Windows 7


    BTW, you could also post MSDN forums to help update the codec for Windows 7.


    Best Regards


    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. ”
    • Marked as answer by Dale Qiao Friday, August 20, 2010 1:08 AM
    Wednesday, August 18, 2010 3:33 AM