How to Fix ASUS X99-A Base System Device Error on Windows 10

The important point is that Base System Device is only a placeholder name. It does not tell you which driver is missing.

The safest fix is:

1. Check the Device Manager error code.
2. Read the device’s Hardware IDs.
3. Confirm the exact ASUS X99 motherboard model.
4. Install the correct ASUS chipset package.
5. Install Intel Management Engine only if a matching unidentified Intel device remains.
6. Recheck Device Manager and identify anything still unresolved.

This avoids guessing and reduces the risk of installing the wrong driver on an older X99 platform.

1. Confirm the Base System Device Error

Right-click Start and open:

Device Manager

Expand:

Other devices

You may see one or more entries such as:

• Base System Device
• PCI Device
• SM Bus Controller
• Unknown device

Right-click the affected entry and choose:

Properties

Check Device status.

A common message is:

The drivers for this device are not installed. (Code 28)

Microsoft defines Code 28 as a condition where the device driver is not installed.

If you see a different error code, record it before doing anything else because the troubleshooting path may change.

2. Read the Hardware ID Before Installing Anything

This is the most useful step in the whole process.

In the device Properties window:

1. Open the Details tab.
2. Open the Property drop-down menu.
3. Select Hardware Ids.
4. Copy the first ID shown.

A PCI device may look similar to:

PCI\VEN_8086&DEV_XXXX&SUBSYS_XXXXXXXX

The VEN_ value identifies the vendor.

For example:

VEN_8086

identifies Intel.

The DEV_ value identifies the specific device.

Do this for every Base System Device entry if there are several.

Two entries can have the same generic name while requiring completely different drivers.

3. Confirm the Exact ASUS X99 Motherboard

ASUS sold several similarly named boards, including:

• ASUS X99-A
• ASUS X99-A/USB 3.1
• ASUS X99-A II

Do not assume the drivers are interchangeable.

Press:

Windows + R

Type:

msinfo32

and press Enter.

Look for:

• BaseBoard Manufacturer
• BaseBoard Product
• BIOS Version/Date

You can also read the model printed directly on the motherboard.

If it says X99-A, use the original X99-A support page.

If it says X99-A II, use the X99-A II support page instead.

This matters because chipset, firmware, USB, storage, and platform-driver packages can differ between board revisions.

4. Open the Official ASUS X99-A Driver Page

For the original X99-A, use the official ASUS support page and select the operating system that matches your Windows installation.

ASUS still lists Windows 10 driver categories for the X99-A.

You can verify the board and available packages on the official ASUS X99-A support page.

Check whether Windows is 64-bit

Open:

Settings > System > About

Look for:

System type

Most X99-A systems running Windows 10 will show:

64-bit operating system, x64-based processor

Choose the matching driver package.

5. Install the Intel Chipset Package First

On an X99-A after a clean Windows installation, the Intel chipset package is the most logical first driver to install when several motherboard devices are unidentified.

On the ASUS support page:

1. Select the correct Windows 10 version.
2. Expand Chipset.
3. Download the Intel chipset package.
4. Extract it if necessary.
5. Run the installer.
6. Restart Windows.

The chipset package supplies Windows with identification and configuration information for Intel platform devices.

That is why several generic Base System Device or PCI entries may disappear after one chipset installation.

6. Recheck Device Manager Before Installing More Drivers

After restarting:

1. Open Device Manager.
2. Expand Other devices.
3. Check which warning entries remain.
4. Expand System devices.
5. Look for newly identified Intel devices.

Do not immediately install every driver from the ASUS page.

If most of the warnings disappeared, the chipset package did its job.

Now focus only on whatever remains.

7. Install Intel Management Engine Only if It Is Relevant

The X99-A support page also lists Intel Management Engine Interface packages.

Install MEI when:

• a matching Intel platform device remains unidentified
• the Hardware ID points to a device handled by MEI
• the ASUS package is intended for your exact board and Windows version

Do not assume every Base System Device needs MEI.

Install it only as part of a controlled driver-identification process.

Restart afterward and check Device Manager again.

8. Use Hardware IDs to Identify Any Remaining Device

If one or two Base System Device entries remain:

1. Open each device’s Properties.
2. Go to Details > Hardware Ids.
3. Copy the first ID.
4. Compare it with the devices supported by the ASUS driver packages.
5. Install only the package that matches that hardware.

Possible categories include:

• chipset
• Management Engine
• storage or RAID
• LAN
• USB controller
• add-in hardware

The Hardware ID should drive the decision.

Do not search for a generic phrase such as:

Base System Device driver download

That usually leads to third-party driver sites rather than a verified driver for the exact hardware.

9. Use Update Driver Only With a Known Driver Folder

Sometimes an ASUS driver package contains .inf files even when the normal installer does not bind them automatically.

In that case:

1. Right-click the unresolved device.
2. Select Update driver.
3. Choose Browse my computer for drivers.
4. Select the extracted ASUS driver folder.
5. Keep Include subfolders enabled.
6. Click Next.

Windows will search the folder for a compatible INF whose Hardware IDs match the device.

If Windows reports that no compatible driver was found, stop there.

Do not force an unrelated INF file with Have Disk simply because it came from Intel or ASUS.

10. Use Windows Update as a Secondary Source

After installing the official ASUS motherboard packages, check Windows Update for any remaining device drivers.

Open:

Settings > Update & Security > Windows Update

Select:

Check for updates

Also check optional driver updates if they are offered.

I would still treat ASUS as the primary source for the motherboard’s chipset and platform packages.

Windows Update is more useful after the board-specific drivers are already installed.

11. What Code 28 Actually Means

Code 28 is primarily a missing-driver condition.

Microsoft documents the message as:

The drivers for this device are not installed. (Code 28)

That means you should focus on matching the device to the correct driver package.

It does not prove that the hardware itself has failed.

If the code later changes to something such as Code 43, the problem has changed and should be diagnosed separately.

For a deeper explanation of that error, see Device Manager Code 43: How to Fix It in Windows 11.

12. If Several Base System Devices Appear After Reinstalling Windows

This is common on older platforms after a clean Windows installation.

A typical pattern is:

1. Windows installs successfully.
2. Basic display and USB work.
3. Device Manager shows several unidentified motherboard devices.
4. The original OEM chipset packages are not yet installed.

Use this order:

1. Intel chipset
2. Intel Management Engine if required
3. storage or RAID driver if used
4. LAN
5. audio
6. USB-related package if required
7. graphics driver
8. any remaining add-in hardware

Recheck Device Manager after each major platform package instead of installing everything at once.

That makes it much easier to see which package actually fixed the device.

13. If the Error Appeared After a BIOS Update

A BIOS update can change how firmware exposes motherboard devices to Windows.

If the Base System Device warning appeared immediately after a BIOS update:

1. Confirm the board model is still detected correctly.
2. Boot Windows normally.
3. Reinstall or repair the chipset package.
4. Install MEI only if needed.
5. Recheck the Hardware IDs.

Do not downgrade the BIOS as the first response to Code 28.

A missing-driver condition should be handled at the driver level first unless there is clear evidence of a firmware problem.

14. Do Not Use X99-A II Drivers on an X99-A

The names are similar, but they are different motherboards.

Use the exact support page for the board printed on the PCB or reported by msinfo32.

This is particularly important for:

• BIOS files
• chipset bundles
• USB drivers
• storage drivers
• board utilities

Using the wrong BIOS is much more dangerous than using the wrong ordinary driver.

15. Do Not Update BIOS Just to Remove Code 28

A BIOS update is not a normal first-line fix for Base System Device Code 28.

Consider a BIOS update only when there is a separate reason, such as:

• CPU compatibility
• documented firmware bug
• stability problem
• ASUS release notes that address your issue

For a straightforward missing-driver warning, install the correct driver first.

16. Windows 10 Support Status Matters, but It Is a Separate Issue

Windows 10 reached the end of standard support on October 14, 2025.

That does not mean the X99-A driver problem cannot be fixed.

ASUS still exposes Windows 10 driver packages for the board, and many X99 systems continue to use Windows 10.

However, the long-term security status of Windows 10 should be considered separately from a Device Manager warning.

Do not attempt an operating-system upgrade merely to remove Base System Device Code 28.

Fix the motherboard driver issue first.

If you later decide to move systems, see How to Upgrade From Windows 10 to Windows 11.

17. Verify the Fix

After installing the required drivers:

1. Restart Windows.
2. Open Device Manager.
3. Expand Other devices.
4. Confirm that Base System Device entries are gone.
5. Check for yellow warning icons.
6. Expand System devices.
7. Confirm the previously unknown hardware now has a real device name.

The real proof is not that an installer says Completed.

The proof is that Windows now identifies the hardware correctly.

Avoid These Common Mistakes

Do not:

• download a generic “Base System Device driver”
• install every ASUS driver at once
• assume every unknown Intel device needs MEI
• use X99-A II packages on an original X99-A
• force unrelated INF files
• rely on random driver-updater utilities
• update BIOS simply because Code 28 appears
• reinstall Windows before checking Hardware IDs
• keep reinstalling the same chipset package after only one different device remains

The fastest reliable path is to identify the device first.

Start with Hardware Ids, confirm the exact motherboard, install the official ASUS X99-A chipset package, restart, and then investigate only the devices that are still unresolved.

That turns a vague “Base System Device” warning into a specific driver problem you can actually solve.