XP conflict with Modems

By Splash
Jul 15, 2005
  1. Hey there

    Just want to clear something up. Is there an issue with XP and modems???

    For some reason if the modem is not switched on before the PC is booted up, XP does not recognize the modem, thereafter you have to go to device manager to scan for new hardware and only then does it pick it up. Is there any way of keeping the modem in device manager besides switching the mode on before booting and scanning for it in device manager????
  2. Triton

    Triton TS Enthusiast Posts: 82

    I have never seen a "good' explanation for this problem with Windows XP and external serial modems. Here is one that I don't agree with;
    "A problem with external modems and Windows XP"

    People using previous versions of Windows and external serial modems became accustomed to being able to turn their external serial modems on after the system was booted and the modem would work.
    I believe the problem relates to how Windows XP handles ACPI (power management)
    In previous version of Windows if the external serial modem was not turned on its driver was still loaded and shown in Device Manager.
    In XP devices are "polled" for their power state when the system is booted. If the device is off it can't respond and its driver is removed from Device Manager and is then listed as a "Hidden/Not Connected" device. It seem XP (with ACPI enabled) tries to treat all PNP devices as "Hot Swap" which they are not.
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