DSU-100 Dual RS-232 Serial Ports
DSU-200/300 Dual RS-422/485 Serial Ports
DSU2-100 Dual RS-232 Serial Ports
DSU2-400 Dual RS-232/422/485 Serial Ports
ESU-100 Eight RS-232 Serial Ports 1-4
ESU-100 Eight RS-232 Serial Ports 5-8
ESU-200/300 Eight RS-422/485 Serial Ports 1-4
Windows Vista, Windows XP, Windows 2000
7.167.16 (2007-02-09) via .inf
USB Serial Adapter Driver File
Malathy (DG Staff Member) on 5-Mar-2007
The following files are found inside the driver download file.
|QTUSBBX2.INF||9.4 KB||9 Feb 2007|
|QTUSBCOM.DLL||19.8 KB||12 Aug 2004|
|QTUSBCOM.SYS||63.6 KB||2 Dec 2005|
|QTUSBPT2.INF||4.4 KB||9 Feb 2007|
|SERQTUSB.VXD||7.8 KB||26 Oct 2001|
|cocpyinf.dll||22.0 KB||16 Apr 2003|
|history.txt||19.2 KB||9 Feb 2007|
|qtucombx.sys||103.3 KB||9 Feb 2007|
|qtucomco.dll||15.4 KB||22 Feb 2006|
|qtucompp.dll||43.5 KB||25 Jan 2007|
|qtucompt.sys||57.9 KB||25 Jan 2007|
|qtusbbx2.cat||12.4 KB||28 Aug 2006|
|qtusbpt2.cat||9.8 KB||28 Aug 2006|
|qtwdmlib.sys||17.9 KB||23 May 2005|
|readme.txt||10.4 KB||24 Aug 2006|
To get the QSU2-400-EMB driver, click the green download button above. After you complete your download, move on to Step 2.
If the driver listed is not the right version or operating system, search our driver archive for the correct version. Enter Quatech QSU2-400-EMB into the search box above and then submit. In the results, choose the best match for your PC and operating system.
Tech Tip: If you are having trouble deciding which is the right driver, try the Driver Update Utility for Quatech QSU2-400-EMB. It is a software utility which automatically finds and downloads the right driver.
Once you have downloaded your new driver, you'll need to install it. In Windows, use a built-in utility called Device Manager, which allows you to see all of the devices recognized by your system, and the drivers associated with them.
In Windows 11, Windows 10 & Windows 8.1, right-click the Start menu and select Device Manager
In Windows 8, swipe up from the bottom, or right-click anywhere on the desktop and choose "All Apps" -> swipe or scroll right and choose "Control Panel" (under Windows System section) -> Hardware and Sound -> Device Manager
In Windows 7, click Start -> Control Panel -> Hardware and Sound -> Device Manager
In Windows Vista, click Start -> Control Panel -> System and Maintenance -> Device Manager
In Windows XP, click Start -> Control Panel -> Performance and Maintenance -> System -> Hardware tab -> Device Manager button
Locate the device and model that is having the issue and double-click on it to open the Properties dialog box.
Select the Driver tab.
Click the Update Driver button and follow the instructions.
In most cases, you will need to reboot your computer in order for the driver update to take effect.
Tech Tip: Driver downloads and updates come in a variety of file formats with different file extensions. For example, you may have downloaded an EXE, INF, ZIP, or SYS file. Each file type has a slighty different installation procedure to follow.
For more help, visit our Driver Support Page for step-by-step videos on how to install drivers for every file type.