Solved: Missing PCI Serial Port Driver in Windows 11/10 (ASUS Q87M-E)

If you have installed Windows 11 or Windows 10 on an ASUS Q87M-E motherboard and Device Manager shows a PCI Serial Port with a yellow warning icon, Windows is missing the correct driver for that device. You may see it listed under Other devices, and opening its properties can show an error such as “The drivers for this device are not installed. (Code 28)”.

This problem is common after a clean Windows installation, especially on older ASUS motherboards such as the Q87M-E. Windows can install drivers automatically for many components, including the chipset, network adapter, audio device, and graphics hardware, but some motherboard-specific devices may still require their original drivers.

The PCI Serial Port entry can be confusing because it does not necessarily mean that your motherboard has a physical serial port that you need to connect to. On the ASUS Q87M-E, this device is generally associated with the motherboard’s Intel Active Management Technology (AMT) / Management Engine interface. The missing driver is usually part of the Intel Management Engine Interface (MEI) package.

Fortunately, this is usually straightforward to fix. In this guide, I’ll show you several ways to identify the device and install the correct driver in Windows 11 or Windows 10.

What Is the PCI Serial Port in Device Manager?

A PCI Serial Port shown in Device Manager is a hardware device connected through the motherboard’s PCI/PCI Express system rather than necessarily being a traditional RS-232 serial connector.

When Windows doesn’t have the appropriate driver, it may display a generic name such as PCI Serial Port instead of identifying the actual hardware.

On the ASUS Q87M-E, the device can be related to Intel’s management and communication components. Because the Q87M-E is based on an Intel Q87 chipset platform and supports Intel business-management technologies, Windows may require the appropriate Intel Management Engine software to properly identify the device.

You can confirm the exact hardware by checking the device’s hardware IDs.

Method 1: Check the PCI Serial Port Hardware ID

Before installing anything, it’s a good idea to identify exactly which device Windows is complaining about.

Press Windows + X and select Device Manager.

Expand Other devices and look for:

PCI Serial Port

You may see a yellow triangle with an exclamation mark next to it.

Right-click PCI Serial Port and select Properties.

Open the Details tab.

Click the Property drop-down menu and select:

Hardware Ids

Windows will display one or more entries similar to:

PCI\VEN_8086&DEV_...

The important part is the VEN value.

For Intel hardware, the vendor ID is:

VEN_8086

If you see an Intel vendor ID, the device is likely one of the Intel motherboard-management components.

You can also copy the complete Hardware ID and search for the corresponding device if you want to verify it before installing a driver.

This step is particularly useful because several different devices can appear under generic names after Windows is installed.

Method 2: Install the Intel Management Engine Interface Driver

The most common solution for the PCI Serial Port problem on the ASUS Q87M-E is to install the appropriate Intel Management Engine Interface (MEI) driver.

The driver allows Windows to communicate correctly with Intel’s management engine hardware integrated into the motherboard platform.

First, download the appropriate driver package for the ASUS Q87M-E.

Because the motherboard is an older platform, the original ASUS driver package may have been designed for Windows 7 or Windows 8.1 rather than Windows 11. That does not necessarily mean it cannot work on Windows 10 or Windows 11.

After downloading the driver package, extract it if necessary.

Open the extracted folder and look for files such as:

Setup.exe

or an installation folder containing the Intel MEI driver.

Right-click the setup program and select Run as administrator.

Follow the installation instructions.

After installation finishes, restart Windows.

Then open:

Device Manager → Other devices

Check whether the PCI Serial Port entry has disappeared.

If it has, the correct driver has been installed.

Method 3: Install the Driver Manually Through Device Manager

If the ASUS setup program refuses to install because it doesn’t recognize Windows 11, you can try installing the driver manually.

First, extract the driver package.

Then open Device Manager.

Right-click PCI Serial Port and select:

Update driver

Choose:

Browse my computer for drivers

Select the folder containing the extracted Intel MEI driver.

Make sure Include subfolders is checked.

Click Next.

Windows will search the folder for a compatible driver.

If it finds the appropriate driver, Windows will install it automatically.

Restart the computer afterward.

This method can sometimes work even when the manufacturer’s setup utility doesn’t run correctly on a newer version of Windows.

Method 4: Install the ASUS Q87M-E Chipset and Motherboard Drivers

Another important step is installing the motherboard’s chipset-related drivers.

After a clean Windows installation, don’t rely exclusively on Windows Update. Windows may install generic drivers that allow the system to function but don’t provide complete identification for every motherboard component.

Download the available drivers for the ASUS Q87M-E motherboard.

The most important packages to consider are:

• Intel chipset driver
• Intel Management Engine Interface driver
• Intel Rapid Storage Technology driver, if required
• LAN driver
• Audio driver
• USB-related motherboard drivers, if applicable

Start with the chipset driver and Intel Management Engine Interface driver.

Install them and restart Windows.

Then check Device Manager again.

If the PCI Serial Port was caused by the missing Intel management driver, it should now be properly identified.

Method 5: Use the Hardware ID to Find the Exact Driver

If installing the MEI driver doesn’t solve the problem, don’t continue installing random drivers.

Instead, use the Hardware ID to determine exactly what Windows is detecting.

Open:

Device Manager → PCI Serial Port → Properties → Details → Hardware Ids

Copy the first line.

It may look something like:

PCI\VEN_8086&DEV_XXXX&SUBSYS_XXXX...

The VEN_8086 identifies Intel as the hardware vendor.

The DEV_XXXX portion identifies the particular Intel device.

The device ID is especially important because Intel has produced many different management and communication devices across different generations of processors and chipsets.

Once you know the exact device ID, you can match it with the appropriate driver package instead of guessing.

This is also useful if the PCI Serial Port isn’t actually the Intel Management Engine interface on your particular configuration.

Method 6: Run Windows Update and Optional Driver Updates

Windows Update can sometimes find a compatible driver automatically.

Open:

Settings → Windows Update

Click:

Check for updates

Allow Windows to install all available updates.

Then check the optional driver section if it is available:

Windows Update → Advanced options → Optional updates → Driver updates

Look for Intel or motherboard-related drivers.

Install the relevant driver and restart the computer.

After restarting, open Device Manager again.

Keep in mind that Windows Update may not always provide the original driver for older hardware. If the PCI Serial Port remains unresolved, use the manufacturer’s driver or identify the hardware using its Hardware ID.

Method 7: Use Device Manager’s Automatic Driver Search

You can also allow Windows to search automatically for a driver.

Right-click PCI Serial Port.

Select:

Update driver

Then select:

Search automatically for drivers

Windows will search its available driver database and Windows Update service.

If a compatible driver is found, Windows will install it.

If Windows says:

The best drivers for your device are already installed

but the PCI Serial Port still has a yellow warning symbol, don’t assume that the correct driver is actually installed.

Windows sometimes has no appropriate driver in its current driver store.

In that situation, use the manual installation method or obtain the driver package from ASUS.

Method 8: Check Whether the Driver Is Already Installed but the Device Is Not Identified

Sometimes the required Intel driver is partially installed but Windows has not correctly associated it with the device.

To investigate this, open:

Device Manager → PCI Serial Port → Properties → Driver

Check the information shown under:

• Driver Provider
• Driver Date
• Driver Version

If these fields are blank or show Microsoft as the provider, Windows may be using a generic device entry.

You can also select:

Driver Details

to see whether Windows has associated any driver files with the device.

If no driver files are listed, install the motherboard’s Intel MEI driver manually.

How to Find the Correct Driver Without Guessing

If you’re unsure whether the PCI Serial Port is actually the Intel Management Engine device, the safest approach is to use the Hardware ID.

Open:

Device Manager → PCI Serial Port → Properties → Details → Hardware Ids

Copy the complete first entry.

The important sections are:

VEN — hardware manufacturer

DEV — device type

SUBSYS — motherboard-specific subsystem information

REV — hardware revision

For example, an Intel device will normally contain:

VEN_8086

Once the exact ID is known, you can match it with the appropriate driver.

This is much safer than downloading a random “PCI Serial Port driver” from an unknown driver website.

Final Solution for ASUS Q87M-E

For most ASUS Q87M-E systems where Windows 10 or Windows 11 displays PCI Serial Port under Other devices, the solution is to install the correct Intel motherboard-management driver, particularly the Intel Management Engine Interface (MEI) driver, after confirming the hardware ID.

The recommended order is simple:

1. Open Device Manager.
2. Right-click PCI Serial Port.
3. Open Properties → Details → Hardware Ids.
4. Confirm the vendor and device ID.
5. Install the appropriate ASUS/Intel chipset and Management Engine driver.
6. If the setup program doesn’t work, extract the package.
7. Install the driver manually through Device Manager.
8. Restart Windows.
9. Check Device Manager again.

You should no longer see the PCI Serial Port listed as an unknown device.

The important thing is not to search for a generic “PCI Serial Port driver.” That name describes how Windows currently sees the hardware, not necessarily what the hardware actually is. Identifying the device through its Hardware ID gives you a much more reliable way to select the correct driver.

Frequently Asked Questions

1. What driver fixes PCI Serial Port on ASUS Q87M-E?

On the ASUS Q87M-E, the PCI Serial Port is commonly associated with Intel motherboard-management hardware, so installing the appropriate Intel Management Engine Interface (MEI) driver is an important first step. Confirm the Hardware ID before installing if you want to be certain.

2. Is the PCI Serial Port a physical serial port?

Not necessarily. The name is a generic Windows device description. A PCI Serial Port entry can represent an internal motherboard device rather than a physical RS-232 connector.

3. Can I use the ASUS Q87M-E driver on Windows 11?

Some older ASUS drivers were designed for earlier versions of Windows. Depending on the driver, Windows 11 may still accept a compatible driver, while some older installation programs may not run. Manual installation through Device Manager can sometimes help.

4. How do I know which driver I need?

Check Device Manager → PCI Serial Port → Properties → Details → Hardware Ids. The VEN and DEV values identify the hardware and allow you to match it with the appropriate driver instead of installing a random PCI Serial Port driver.