What is ptserial?

Ptserial.sys is a Windows driver. A driver is a small software program that allows your computer to communicate with hardware or connected devices. This means that a driver has direct access to the internals of the operating system, hardware etc. The free file information forum can help you determine if ptserial.sys is a Windows system file or if it belongs to an application that you can trust.

Run a free scan to check for ptserial drivers in need of updating

Ptserial.sys file information

The process known as HSP Modem Serial Device Driver or HSP Modem Serial Device Driver for (version NT 5.0) belongs to software W2K Pctel Serial Device Driver or W2K Conexant Serial Device Driver by PCTEL, INC ( or Conexant Systems (

Description: Ptserial.sys is not essential for the Windows OS and causes relatively few problems. Ptserial.sys is located in the C:\Windows\System32\drivers folder. Known file sizes on Windows 10/8/7/XP are 135,292 bytes (33% of all occurrences), 131,676 bytes and 5 more variants. 
The driver can be started or stopped from Services in the Control Panel or by other programs. The program is not visible. The service has no detailed description. Ptserial.sys is not a Windows core file. ptserial.sys appears to be a compressed file. Therefore the technical security rating is 24% dangerous, however you should also read the user reviews.

Recommended: Identify ptserial.sys related errors

Important: Some malware disguises itself as ptserial.sys, particularly when not located in the C:\Windows\System32\drivers folder. Therefore, you should check the ptserial.sys process on your PC to see if it is a threat. We recommend Security Task Manager for verifying your computer's security. This was one of the Top Download Picks of The Washington Post and PC World.


User Comments

i try to instal a modem and the driver ask for ptserial.sys
  fernando garcia  
important for windows xp
motorola fax 56k driver can't install, that problem is ptserial.sys
i had a problem with that cuase when i updated my system to windows 7 i was getting bsod all time. i think its a driver but i dont know what it does.

Rating chart

Summary: Average user rating of ptserial.sys: based on 9 votes with 4 user comments. 5 users think ptserial.sys is essential for Windows or an installed application. 3 users think it's probably harmless. One user thinks ptserial.sys is dangerous and recommends removing it. 2 users don't grade ptserial.sys ("not sure about it").

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Best practices for resolving ptserial issues

A clean and tidy computer is the key requirement for avoiding problems with ptserial. This means running a scan for malware, cleaning your hard drive using cleanmgr and sfc /scannow, uninstalling programs that you no longer need, checking for Autostart programs (using msconfig) and enabling Windows' Automatic Update. Always remember to perform periodic backups, or at least to set restore points.

Should you experience an actual problem, try to recall the last thing you did, or the last thing you installed before the problem appeared for the first time. Use the resmon command to identify the processes that are causing your problem. Even for serious problems, rather than reinstalling Windows, you are better off repairing of your installation or, for Windows 8 and later versions, executing the DISM.exe /Online /Cleanup-image /Restorehealth command. This allows you to repair the operating system without losing data.

To help you analyze the ptserial.sys process on your computer, the following programs have proven to be helpful: Security Task Manager displays all running Windows tasks, including embedded hidden processes, such as keyboard and browser monitoring or Autostart entries. A unique security risk rating indicates the likelihood of the process being potential spyware, malware or a Trojan. Malwarebytes Anti-Malware detects and removes sleeping spyware, adware, Trojans, keyloggers, malware and trackers from your hard drive.

Other processes

ptserial.sys [all]