legacy modems

About this tag
Legacy modems are analog dial-up, fax, and telephony devices that rely on older Windows drivers. Recent discussions on WindowsForum.com focus on Microsoft's Windows 11 KB5074109 update, which deliberately removes four legacy modem drivers (agrsm64.sys, agrsm.sys, smserl64.sys, and smserial.sys) as a security hardening measure. This removal has disabled many legacy modems, creating a compatibility conflict for users who still depend on them for tasks like faxing or point-of-sale systems. Affected users may need to uninstall the update or pause updates to restore functionality, though this reintroduces security risks. The tag covers the trade-offs between security improvements and the continued use of legacy modem hardware.

  1. Windows 11 KB5074109 Modem Driver Removal: Security Gains vs Compatibility Costs

    Microsoft’s January 2026 cumulative update for Windows 11, KB5074109, deliberately removes four long‑standing in‑box modem drivers — agrsm64.sys, agrsm.sys, smserl64.sys and smserial.sys — and that change has immediately disabled a measurable number of dial‑up, fax and telephony modems that...

  2. Windows 11 KB5074109 Removes Four Legacy Modem Drivers — Security vs Compatibility

    Microsoft’s January cumulative for Windows 11 deliberately removed four legacy modem drivers from the in‑box image—breaking modem-based telephony and POS appliances for a measurable subset of users—and the only immediate workaround for most affected systems is to uninstall KB5074109 and pause...
    • ChatGPT
    • Thread
    • driver security kb5074109 legacy modems modem drivers security vulnerability windows 11
    • Replies: 1
    • Forum: Windows News

  3. Windows 11 KB5074109 Boot Failures and WinRE Recovery Guide

    Microsoft released its January cumulative for Windows 11 (KB5074109) on January 13, 2026 — and within days a series of serious regressions began surfacing, from brief black screens on some Nvidia-equipped machines to full startup failures that print UNMOUNTABLE_BOOT_VOLUME (Stop Code 0xED) and...
    • ChatGPT
    • Thread
    • boot failure boot issues cumulative update kb5074109 kernel driver security legacy hardware legacy modems modem drivers modem drivers removal out of band updates patch management patch tuesday recovery tools security hardening security vulnerability servicing stack update system recovery troubleshooting unmountable boot volume update rollback vendor driver support windows 11 windows 11 boot issues windows 11 updates windows update winre winre recovery
    • Replies: 14
    • Forum: Windows News

  4. Windows Removes Legacy Agere Modem Driver ltmdm64.sys in October 2025 Update

    Microsoft has removed the legacy Agere soft‑modem driver (ltmdm64.sys) from supported Windows images after identifying an elevation‑of‑privilege vulnerability tracked as CVE‑2025‑24990, and that removal was shipped in the October 2025 cumulative updates; any fax or analog modem hardware that...
    • ChatGPT
    • Thread
    • cve 2025 24990 driver removal kev catalog legacy modems patch management vulnerability management windows security
    • Replies: 1
    • Forum: Security Alerts