fxsperf.dll is a genuine Microsoft Windows component called Microsoft Fax PerfMon DLL. If Windows says fxsperf.dll is missing, not found, or could not be loaded, repair the Windows component that owns it rather than downloading a replacement DLL.
The file belongs to Microsoft Fax Server and supports legacy fax performance counters. It is not part of Visual C++, DirectX, .NET, or a general-purpose game runtime. The safest first repair is to run DISM and SFC, then repair or reinstall the Fax feature if Windows still cannot load it.
What fxsperf.dll does
fxsperf.dll is a Windows performance-counter provider associated with Microsoft Fax services. Performance Monitor and related Windows components can load performance DLLs to collect diagnostic and usage data.
Microsoft describes these files as providers that expose performance-counter data to Windows monitoring tools. They are not ordinary application libraries, COM controls, or ActiveX components that you normally register with regsvr32.
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Microsoft Fax Server includes the Fax Server role, Fax service, Fax Service Manager, Windows Fax and Scan, and the fax printer. The exact feature availability depends on whether you are using Windows Server or a client edition of Windows.
| Item | Verified identification |
|---|---|
| File | fxsperf.dll |
| Description | Microsoft Fax PerfMon DLL |
| Product association | Microsoft Fax Server |
| Publisher | Microsoft Corporation |
| Category | Microsoft Windows component |
| Main function | Legacy fax performance-counter provider |
| Runtime type | Not Visual C++, DirectX, or .NET |
The presence of an error does not necessarily mean you actively use faxing. A stale performance-counter registration can still request the file after the Fax feature has been removed. Conversely, a damaged or incomplete Fax installation can cause the same message when Fax services or Performance Monitor start.
Error messages you may see
The wording varies depending on which program requested the file:
The file fxsperf.dll is missingFxsperf.dll not foundThis application failed to start because fxsperf.dll was not foundThe file fxsperf.dll is missing or corruptedError loading fxsperf.dll. The specified module could not be foundfxsperf.dll is either not designed to run on Windows or it contains an error
Write down the complete message and the executable that displayed it. Also note when the error appears:
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- During Windows startup
- When opening Performance Monitor
- When starting a Fax service
- When opening Windows Fax and Scan
- When launching one old application or game
- Immediately after an update, cleanup operation, or security detection
That timing helps distinguish a damaged Windows component from a stale registration or an application with an incorrect dependency.
Before repairing anything
First identify whether this is a Windows component problem or an old program problem.
Check whether Fax features are installed
On Windows 11:
- Right-click Start and select Settings.
- Select System.
- Select Optional features.
- Choose View features.
- Search for
fax. - Note whether a relevant Fax feature is available or already installed.
On Windows 10:
- Open Settings.
- Select Apps.
- Select Optional features.
- Review the installed features and use Add a feature if available.
- Search for
fax.
Feature names and availability vary by Windows edition and release. Do not assume that every Windows 10 or Windows 11 installation provides the same Fax components.
On Windows Server, the relevant component is generally the Fax Server role rather than a normal client optional feature.
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Check Windows Security Protection History
Windows Security may have quarantined a legitimate system file, or it may have detected a malicious file with a similar name.
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- 2 RJ11 Ports, you can set your telephone, fax system. Up to 56K data download, 48K data upload, and 14.4K fax communication.Provide Quick Connect and Modem-on-Hold features.
- Open Start and search for Windows Security.
- Select Virus & threat protection.
- Select Protection history.
- Review recent detections involving
fxsperf.dllor the program that requested it. - Open a detection to view its path and action.
Do not restore a file merely because its name looks like a Microsoft file. Microsoft warns that restoring a detected item can expose the device again. Restore or allow it only after confirming that it came from a legitimate Windows component and that the system is otherwise clean. If the location is unusual, run a full scan and consider an offline scan before restoring anything.
Fix 1: Install pending Windows updates and restart
A failed feature installation or incomplete update can leave Windows component files out of sync.
- Open Settings.
- Select Windows Update.
- Select Check for updates.
- Install available updates.
- Restart Windows, even if it does not immediately require a restart.
- Test the program or Windows feature that produced the error.
On Windows 10, open Settings → Update & Security → Windows Update and select Check for updates.
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If the error began immediately after an update, restart first and then run the repair commands below. If Windows Update itself is failing, resolve that issue before repeatedly attempting to reinstall the Fax feature.
Fix 2: Repair Windows with DISM and SFC
This is the strongest first-line fix because fxsperf.dll belongs to a Windows component. DISM repairs the Windows component store, and SFC then checks protected system files against that repaired source.
Run DISM
- Open Start.
- Type
Command Prompt. - Right-click Command Prompt.
- Select Run as administrator.
- Approve the User Account Control prompt.
- Enter this command:
DISM.exe /Online /Cleanup-Image /RestoreHealth
- Press Enter.
- Wait for the operation to finish.
The scan can take time and may appear to pause at a percentage. Do not close the window while it is running.
Run System File Checker
After DISM completes, enter:
sfc /scannow
Press Enter and wait for verification to reach 100 percent. Restart Windows when it finishes, then test the original action again.
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If you would rather avoid hunting through several repair commands and interpreting repeated SFC or DISM results, Outbyte PC Repair can scan for system problems and show what it identifies; its free scan shows the issues, while repair is handled by the full version, and it is not required for this Microsoft-supported fix.
Interpret the result
SFC commonly reports one of these outcomes:
- Windows Resource Protection did not find any integrity violations: protected files were not damaged, so investigate the Fax feature, a stale registration, or the parent application.
- Windows Resource Protection found corrupt files and successfully repaired them: restart and test again.
- Windows Resource Protection found corrupt files but was unable to fix some of them: run DISM again, review the CBS log, and continue with feature repair or Windows recovery if the problem persists.
Do not copy a replacement DLL into a system folder after SFC reports a problem. That bypasses Windows servicing and can leave the installation with mismatched files.
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- Data/Fax Mode: Comply with V.92, V.90 and V.42, V.42bis / MNP5 protocol. Meets V.17, V.29, and V.27ter Group 3 fax protocols. For GRIS fax cats can dial the Internet, send and receive faxes, but do not support voice calls.
- Tech Specs: Up to 56k data download, 48k data upload, and 14.4k fax communication. The 56k data/fax modem uses USB 2.0 Type A with a full speed of 56kb/s.
- Compatibility: Standard and expanded AT command set compatibility. Provides fast connection and maintenance function on the modem.
Fix 3: Repair or reinstall the Fax feature
If DISM and SFC complete but the error remains, the Fax component may be absent or incompletely installed.
On supported Windows Server editions
- Open Server Manager.
- Select Manage.
- Select Add Roles and Features.
- Choose Role-based or feature-based installation.
- Select the target server.
- On Server Roles, select Fax Server.
- Accept the required management tools.
- Complete the installation.
- Restart if prompted.
- Test the Fax service or the program that generated the error.
Microsoft’s Fax Server installation guide describes the role and its related management components. The documentation is for a server release, so do not assume that the same role exists on every client edition.
On Windows client editions
If your edition offers Windows Fax and Scan or a related Fax optional feature:
- Open Settings.
- Go to System → Optional features on Windows 11, or Apps → Optional features on Windows 10.
- Select View features or Add a feature.
- Search for
fax. - Select the available Fax feature.
- Choose Next, then Install.
- Restart Windows if requested.
- Test the affected feature.
Microsoft’s Windows Fax and Scan feature guidance illustrates this route, but feature availability is not universal across every current Windows build.
If the feature is already installed, remove it, restart, install it again, and restart once more. Follow that with another DISM and SFC pass if the installation reports an error.
Fix 4: Determine whether a stale performance-counter registration is responsible
A stale performance-counter registration can ask Windows to load fxsperf.dll even though the Fax feature is no longer installed. In that case, the message does not prove that you need to download the file.
Look for these clues:
- The error appears only when opening Performance Monitor.
- No Fax feature is installed.
- Windows starts normally and no Fax service is used.
- One old monitoring tool triggers the message.
- The error began after removing an older Windows feature.
You can inspect the Windows Event Viewer for the requesting service or executable:
- Right-click Start.
- Select Event Viewer.
- Expand Windows Logs.
- Check System and Application around the time of the error.
- Also review Applications and Services Logs for entries related to performance counters, Fax, or the parent program.
- Record the event source, event ID, executable name, and full path.
Microsoft documents the performance-counter registry model, but registry editing is not a safe first repair for this problem. Do not delete performance-counter entries manually unless you have identified the exact obsolete registration, backed up the registry, and understand which service owns it.
Repairing or reinstalling the Fax feature is safer than deleting registry entries. If Fax is intentionally absent and only a legacy monitoring program complains, repair or remove that monitoring program instead.
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Fix 5: Repair the old application that requests the file
If Windows works normally and only one old program asks for fxsperf.dll, the program may have an incorrect dependency or an installer that expects an older Fax environment.
Try this sequence:
- Open Settings.
- Select Apps.
- Select Installed apps on Windows 11, or Apps & features on Windows 10.
- Find the affected program.
- Open its menu and select Uninstall, or use its built-in repair option if available.
- Restart Windows.
- Download or reinstall that program only from its publisher’s official source.
- Test it again.
If the program is business software, contact its vendor and provide the exact executable name and error text. A modern application should not require a random copy of a legacy Windows Fax performance provider.
Do not assume that a game error mentioning this file means the game needs a game DLL. The parent application may be launching an old utility, scanner, printer tool, or monitoring component alongside the game.
Fix 6: Check drivers only when the error follows a hardware or fax change
Drivers are not the normal cause of a missing fxsperf.dll, but a fax modem, multifunction printer, scanner, or communications device can expose the problem after a driver or feature change.
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A free scan shows the junk files, broken settings and background clutter dragging Windows down - then fixes them in one click.Free scan · Windows 10 & 11To inspect the device:
- Right-click Start.
- Select Device Manager.
- Expand Modems, Print queues, Printers, Imaging devices, and Universal Serial Bus controllers as relevant.
- Look for a yellow warning icon.
- Right-click the affected device.
- Select Properties and review the General and Events tabs.
- Select Update driver and choose Search automatically for drivers.
- If the issue began after an update, open Properties → Driver and use Roll Back Driver when available.
- Restart Windows and test again.
Do not replace a Windows component DLL with a driver package. Install drivers from Windows Update or the hardware manufacturer, matching your Windows edition and system architecture.
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Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.What not to do
Do not download fxsperf.dll from a random DLL website
A standalone download can be:
- Modified or malicious
- Intended for a different Windows release
- The wrong architecture
- Unsigned or incorrectly signed
- Incompatible with the installed Fax component
- Placed in the wrong system directory
- Unable to repair the underlying feature or registration
There is no verified Microsoft redistributable package specifically for fxsperf.dll. The safe sources are Windows servicing, Microsoft feature installation, Windows Update, System Restore, and supported Windows recovery.
Do not copy it into System32, SysWOW64, or the program folder
A historical third-party record may describe an old 32-bit file, but that does not establish where a current Windows installation should place it. On 64-bit Windows, directory handling is architecture-sensitive, and a 32-bit historical record does not tell you which copy belongs on your system.
Use DISM, SFC, or the Windows feature installer so Windows selects the correct component files.
Do not run regsvr32 as a generic DLL fix
regsvr32 is intended for DLLs that provide registration entry points such as DllRegisterServer. A performance-counter provider is not automatically a COM DLL.
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Running:
regsvr32 fxsperf.dll
is therefore not a standard repair. It may produce an error stating that DllRegisterServer was not found, while leaving the real component problem untouched. Microsoft explains the registration behavior of regsvr32 and the purpose of DllRegisterServer.
Do not install Visual C++, DirectX, or .NET to fix this file
Those packages solve different dependency problems. fxsperf.dll is associated with Microsoft Fax Server and Windows performance counters, not with those runtimes. Installing unrelated redistributables adds software without repairing the owning Windows feature.
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System Restore is useful when the error began after a driver installation, update, cleanup utility, or failed feature change.
- Press Windows key + R.
- Enter:
rstrui.exe
- Press Enter.
- Choose a restore point from before the problem began.
- Review the affected programs and drivers.
- Confirm the restore.
- Allow Windows to restart.
You can also open Control Panel → Recovery → Open System Restore. Microsoft’s System Restore guidance explains that it normally rolls back system files, registry settings, drivers, and installed programs without changing personal files.
Advanced checks when the error persists
If the file still fails after component repair and Fax feature installation:
- Check the CBS log for SFC repair failures.
- Review Event Viewer for the requesting executable and service.
- Confirm whether the error occurs in a clean boot.
- Check Windows Security Protection History again.
- Verify the digital signature of any existing file rather than trusting its filename.
- Compare the behavior on Windows client versus Windows Server.
- Record whether the system is 32-bit or 64-bit, without assuming that an old file record applies to it.
- Check whether a recent update or upgrade remains incomplete.
- Test the original application after a clean reinstall.
If Windows servicing remains damaged, use Microsoft’s Windows recovery options, including supported reset or in-place repair choices appropriate for your installation. Back up important files before a major recovery operation.
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Is fxsperf.dll malware?
The legitimate file is a Microsoft component associated with Microsoft Fax Server. However, a Microsoft-looking filename is not proof of authenticity. If the file exists in an unexpected location or was flagged by Windows Security, verify its signature and scan the system before restoring it.
Is fxsperf.dll part of Windows 10 or Windows 11?
It is associated with Windows Fax components, but the feature and file availability vary by edition and release. Do not rely on an old file listing to determine what belongs on a current Windows installation.
Do I need this file if I never send faxes?
Not necessarily. A stale performance-counter registration or old program can request it even when you do not use fax functionality. Identify the requesting executable before installing or removing anything.
Can I fix it by installing Visual C++ Redistributable?
No. fxsperf.dll is not identified as a Visual C++ runtime file. Repair Windows components and the Fax feature instead.
Should I register it with regsvr32?
Normally, no. It is a performance-counter DLL, not automatically a COM or ActiveX library. Use Windows feature repair and component servicing.
What is the safest fix for a missing fxsperf.dll?
Run DISM followed by SFC, restart, and then repair or reinstall the Windows Fax feature if the error remains. If only one old application requests the file, repair that application and contact its publisher.
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