W&T connects
Interfaces for TCP/IP, Ethernet, RS-232, RS-485, USB, 20mA, glass and plastic fiber optic cable, http, SNMP, OPC, Modbus TCP, I/O digital, I/O analog, ISA, PCI
Current driver versions:

COM Port Redirector Legacy

Com-Servers, LAN-Modems, Soft-Links under Windows NT/2000/XP/2003/Vista/7/2008/8/8.1/10 incl. 64-bit- and Server-Editions


Connect a Com-Server, a LAN modem or a Web-IO with serial interface to the network, establish a virtual COM port on your system and your serial application is network-capable; without having to program a single line of code.

Win 10 function update 1903 deletes core drivers for COM Port Redirector

After an update of Win10 to version 1903 the core drivers for the COM Port Redirector legacy are no longer there. An error message only appears when the configuration tool for the COM Port Redirector is started or an application attempts to open a virtual COM port.

Solution: Perform a repair installation or update to the available current version. Alternately as administrator switch in an input prompt to the installation directory of the COM Port Redirector (... Program Files (x86)/W&T VirtualComm) and there start "Setup.exe /install".

Date Changes and comments Revision
July 22, 2019
  • Corrected error message and automatic repair after update to Win10 Build 1903
3.91
EXE download
(approx. 3.56 MB)
July 9, 2019
  • NEW: Filters for outside line in dial string for virtual modem ports
  • Manual expanded
3.90
EXE download
(approx. 3.56 MB)
April 18, 2019
  • Optimizing of the Config Tool
  • Connection opening of encrypted modem ports corrected
3.89
ZIP download
(approx. 3.11 MB)
April 5, 2018
  • Installation problem on unpatched Win7 systems fixed
3.88
EXE download
(approx. 3.57 MB)
August 30, 2017
  • Attestation signing (fixes problems with current Win 10 versions in conjunction with Secure Boot)
3.86
EXE download
(approx. 3.53 MB)
August 9, 2017
  • Optimizations for the Portmap tool
3.85 EXE - approx. 3.49MB
[on request]
January 3, 2017
  • Optimizing of failed reconnects when there is simultaneous data sending
  • SHA256 signature for the installation exe
  • Cosmetic corrections for the version information details
3.84 EXE - approx. 3.52MB
[on request]
October 26, 2016
  • Optimizations for virtual modem ports and Soft-Link
  • Cosmetic corrections in Config tool
3.83 EXE - approx. 3.47MB
[on request]
June 13, 2016
  • NEW: SSL/TLS encrypted connections to AT modem emulators with firmware version >= 1.38
  • Optimized connection handling for NAT connected virtual machines
  • Firewall-optimized reconnect after connection interruptions
  • Optimized name resolution
3.80 EXE - approx. 3.47MB
[on request]
July 24, 2015
  • Port management in configuration tool corrected (deleting, creating, applying)
  • Modem ports: ati replies configurable
3.73 EXE - approx. 2.89MB
[on request]
January 5, 2015
  • Installation optimized
  • Configuration tool optimized (Start now possible for example without Admin rights)
  • Corrections/additions to the optional tools Companion and Portmap
3.71 EXE - approx. 2.89MB
[on request]
June 30, 2014
  • Serial API: Event handling revised/corrected
  • Optional baud rate-dependent write delay corrected
  • Cosmetic corrections in Config tool and Companion
3.62 EXE - approx. 2.09MB
[on request]
April 30, 2014
  • 32-bit core driver signed (Vista Secure Boot)
  • New setup as *.exe with language option
  • DNS resolution improved
3.60 EXE - approx. 2.08MB
[on request]
February 10, 2014
  • Logging problem fixed
  • Support for the freely configurable baud rate divisor of the Com-Server
  • Installation problem under Win NT fixed
3.53 MSI - approx. 1.44MB
[on request]
September 12, 2013
  • Saving of changed setting corrected
  • Display of the application that opens a COM port in Portmap
  • Portmap installation optimized
  • Context help revised
3.51 MSI - approx. 1.41MB
[on request]
November 22, 2012
  • Since v. 3.40 existing installation problem on computers without COM ports eliminated
  • New: WMI support
  • DNS client optimized
3.50 MSI - approx. 1.4MB
[on request]
August 8, 2012
  • Expanded registration of virtual COM ports
  • Configuration file output improved
  • Renumbering of virtual COM ports optimized
  • "Read device name" feature corrected
3.40 MSI - approx. 1.4MB
[on request]
September 27, 2011
  • Combined installation package (German, English, 32-bit, 64-bit)
  • *msi download format
  • Renumbering of COM ports when there is a collision optimized
3.30 MSI - approx. 1.3MB
[on request]
July 8, 2011
  • Renumbering of COM ports optimized
  • Portmap can uninstall COM ports
3.24 ZIP - approx. 833 kB
[on request]
May 20, 2011
  • LAN modem ports connection opening under Windows 7 optimized
  • File selection boxes function under Windows NT
3.23 ZIP - approx. 818 kB
[on request]
February 28, 2011
  • New option: Opening COM ports possible even when a Com-Server cannot be reached
  • Update behavior and installation routine optimized
  • DNS resolution improved
3.21 ZIP - approx. 814 kB
[on request]
June 25, 2010
  • Optimized registration of virtual ports (rudimentary DeviceNode/DeviceInterface entries)
  • Optimized DNS resolution incl. Companion tool
  • Optional support of PURGE_TXCLEAR implemented
3.14 ZIP - approx. 731 kB
[on request]
June 5, 2009
  • Online help for modem ports expanded
  • Loading of the LAN modem configuration corrected
3.10 ZIP - approx. 717 kB
[on request]
May 11, 2009
  • Installation/uninstallation under NT optimized
  • Cosmetic changes to the configuration tool
  • Problems with non-delayed COM-Open loops in connection   with missing network connection resolved
3.08 ZIP - approx. 714 kB
[on request]
March 19, 2009
  • Installation problems under Win NT eliminated
  • Companion tool integrated into installation package
3.04 ZIP - approx. 702 kB
[on request]
November 26, 2008
  • NEW: Configuration tools as standard application
  • NEW: Expanded Tool Portmap.exe (opening COM ports)
  • Change in asymmetrical Xon/Xoff protocol (fInx =! fOutx)
  • Optimizing for operation with security software
  • Optimized installation routine

After installing Version 3.02 the configuration tool for the COM Port Redirector is no longer in the Control Panel, but rather in the Windows Start menu in the program groupW&T COM Port Redirector. As part of the installation it is possible to create a corresponding desktop icon.

3.02 ZIP - approx. 562 kB
[on request]
May 19, 2008
  • NEU: Installation per MSI
  • NEW: Configuration tool also in the Windows Start menu
  • NEW: File import/export of the inventory list and settings
  • Revised and expanded online help/manual
  • Load-optimized control connection
  • Optimized handling of invalid baud rates
  • Expanded configuration tool test function
  • Various cosmetic corrections
  • Problem when starting the configuration tool/applet remedied
3.00 ZIP - approx. 785 kB
[on request]
January 17, 2008
  • Optimized internal queue handling
  • Changed control applet to Unicode
2.81 ZIP - approx. 504 kB
[on request]
August 23, 2007
  • Deleting COM ports was not possible in Version 2.73
  • NEW: Numerical specification of the TCP port for supporting NAT
2.80 ZIP - approx. 501 kB
[on request]
June 28, 2007
  • Max. length of domain names expanded
  • Support for DHCP-assigned DNS servers
  • Optimized error messages
2.73 ZIP - approx. 501 kB
[on request]
January 25, 2007
  • NEW: Support for Windows Vista
  • NEW: Freely editable comments for each COM port
  • NEW: Dialog-free installation by running setup.exe with option /q
2.70 ZIP - approx. 474 kB
[on request]
October 19, 2006
  • Optimized reconnect behavior for interrupted network connections
  • Default parity changed from Even to No
  • TCP keepalive for data port activated
2.64 ZIP - approx. 469 kB
[on request]
March 28, 2006
  • NEW: Support for 64-bit Windows systems
  • Cosmetic changes to control applet
  • Internal adjustments to the LAN modem ports
2.62 ZIP - approx. 468 kB
[on request]
February 14, 2006
  • Optimized timing and handling of the connections under Windows 2000/XP/2003
2.61 ZIP - approx. 296 kB
[on request]
January 4, 2006
  • Internal modifications for operating on multi-processor systems
  • Renumbering of COM ports without having to restart the computer under XP/2003 optimized
  • Conflict checking of the control applet revised
2.60 ZIP - approx. 296 kB
[on request]
December 6, 2005
  • Problem in restoring the connection to the COM-Server remedied
  • Cosmetic corrections in Setup and Control Applet
2.54 ZIP - approx. 296 kB
[on request]
October 5, 2005
  • NEW: DNS Support; target devices can now be specified by their host name
  • Control of the Control applet optimized
  • Error handling for MDL allocation corrected
2.53 ZIP - approx. 296 kB
[on request]
April 5, 2005
  • Closing of the TCP connection to the Com-Server corrected
  • Interaction with antivirus software optimized
2.50 ZIP - approx. 291 kB
[on request]
December 13, 2004
  • Optimized utilization of the send and receive buffers
  • Recommended value range for connect timeout extended
2.49 ZIP - approx. 287 kB
[on request]
April 17, 2004
  • Optimized handling of repeated calls to SetCommMask()
2.47 ZIP - approx. 287 kB
[on request]
April 26, 2004
  • Additional function: The status of RI and DCD can be determined manually or as a copy of CTS / DSR
  • Optimizations when operating with soft links and in combination with the companion tool as well as the Windows printer spooler
  • Optical corrections
2.46 ZIP - approx. 287 kB
[on request]
December 17, 2003
  • Additional option: "Discard transmitted data in the case of connection disorders"
  • Process for status queries optimized
2.43 ZIP - approx. 273 kB
[on request]
October 7, 2003
  • Improved diagnostics messages when renumbering ports
  • Optimizations together with W&T Companion Tool
  • Addition of 110 baud (only when used with Highspeed Com-
    Servers firmware version 1.35 and higher)
2.41 ZIP - approx. 267 kB
[on request]
June 24, 2003
  • Takes into account COM ports which are unused but reserved by other programs (e.g., USB interfaces) in Windows 2000
  • Visual corrections of the control applet
2.40 ZIP - approx. 265 kB
[on request]
February 3, 2003
  • Event handling of the modem ports and soft-links Optimized
  • Some visual changes to the control applet
  • Registry configuration expanded
2.34 ZIP - approx. 274 kB
[on request]
October 23, 2002
  • Packet handling of the control connection optimized
2.31 ZIP - approx. 271 kB
[on request]
August 27, 2002
  • System password support for
    connections with Com-Server Highspeed added
2.30 ZIP - approx. 271 kB
[on request]
May 14, 2002
  • Modified handling of event_char
    (affects e.g. problems when accessing the dialup network)
2.25 ZIP - approx. 678 kB
[on request]
March 21, 2002
  • Corrected counter for queued send-data
    (affects problems when accessing Simatic S7 with Step7)
2.24 ZIP - approx. 672 kB
[on request]
January 10, 2002
  • Optimized performance for Soft-Links
2.23 ZIP - approx. 671 kB
[on request]
December 14, 2001
  • Visual corrections in control applet
2.22 ZIP - approx. 135 kB
[on request]
December 12, 2001

Additional functions:

  • LAN-Modem calls can be received
  • Computer-computer couplings (= Soft-Links) are possible
2.21 ZIP - approx. 135 kB
[on request]
August 27, 2001
  • Network side licensing test eliminated
2.20 ZIP - approx. 202 kB
[on request]
July 6, 2001
  • COM Port Redirector for Windows NT/2000
2.11 ZIP - approx. 124 kB
[on request]