fc.exe

What is fc.exe?

fc.exe is the built-in Windows command-line utility used to compare two files or sets of files and report differences. You invoke it from Command Prompt or PowerShell, and it outputs differences or a summary of mismatches for quick integrity checks.

Fc.exe runs as a console process that compares two files and highlights differences. It supports text and binary comparisons, reports the first mismatch, and accepts switches to tailor output. It’s a native Windows utility intended for scripting and quick integrity checks.

Types of fc.exe Processes

• Command-Line Process: Runs as a console process invoked from CMD or PowerShell (one process per invocation).
• Output Handling: Writes results to stdout; exit code signals results.
• Modes: Binary (/B) vs. text (/L) comparison modes select how content is treated.
• Usage in Scripts: Commonly called within batch files or automation tasks for diffs.
• No Recursion: fc.exe compares specified files; it does not recursively scan directories.
• Error Reporting: Non-zero exit codes indicate problems like missing files or access issues.

Is fc.exe Safe?

Yes, fc.exe is safe when it's the legitimate Microsoft Windows system file located in the System32 directory and not tampered with.

Is fc.exe a Virus or Malware?

The real fc.exe is NOT a virus. Malware may masquerade with similar names; verify the path and signature.

How to Tell if fc.exe is Legitimate or Malware

1. File Location: Must be in C:\Windows\System32\fc.exe or C:\Windows\SysWOW64\fc.exe. Any fc.exe elsewhere is suspicious.
2. Digital Signature: Right-click fc.exe → Properties → Digital Signatures. Should show a Microsoft signature such as "Microsoft Windows".
3. Resource Usage: Normal fc.exe usage is minimal; long-running or high CPU when not comparing files is suspicious.
4. Behavior: Fc.exe should run only when invoked by the user or a script. Persistent background activity may indicate compromise.

Why Is fc.exe Running on My PC?

fc.exe runs when a file comparison is requested, often via command prompts, scripts, or automated build checks.

Reasons it's running:

• Active File Comparison: You or a script are actively comparing two files or sets of files.
• Batch or Script Tasks: A batch file or automation workflow invokes fc.exe to perform diffs as part of a larger job.
• Source Control Hooks: CI/CD pipelines or version control hooks call fc.exe to verify changes.
• System Integrity Checks: Maintenance tasks compare critical config or binary files for changes.
• Scheduled Tasks: Scheduled tasks or startup scripts may run fc.exe to monitor file changes.

Can I Disable or Remove fc.exe?

Disabling fc.exe is not generally recommended. It’s a built-in Windows tool used by scripts and admins. You can disable automatic calls from startup tasks or batch jobs, but removing the executable may affect workflows.

How to Stop fc.exe

• Cancel Active Processes: In CMD/PowerShell, press Ctrl+C to stop a running fc.exe invocation.
• Close Related Tasks: Review Task Scheduler or batch scripts that call fc.exe and disable or modify them.
• Check Startup Items: Disable any startup scripts or scheduled tasks invoking fc.exe from Task Manager > Startup or Task Scheduler.
• Modify Scripts: Edit batch files or automation scripts to remove fc.exe calls.
• Alternative Tools: If you need diffing capabilities, consider other tools like WinMerge or Beyond Compare; keep fc.exe for compatibility.

How to Uninstall fc.exe

• ✔ fc.exe is a built-in Windows tool and cannot be uninstalled independently. You can disable or remove scripts that call it, or disable Windows Features that include the FC utility on older Windows versions.
• ✔ For replacing functionality, install a third-party diff tool: WinMerge, Beyond Compare, or Meld.

Common Problems: fc.exe

If fc.exe behaves unexpectedly or returns errors, use these guides to diagnose and fix typical file-diff issues.

Common Causes & Solutions

• Incorrect command syntax or missing file paths: Re-run fc.exe with full paths quoted, e.g. fc "C:\path\to\file1.txt" "C:\path\to\file2.txt"
• Files not found or moved: Verify both file paths exist and are accessible; adjust paths or permissions accordingly.
• Binary vs text mode not specified: Specify mode explicitly: use /B for binary or /L for text, depending on content.
• Large files causing long run times: Limit file sizes for compare or preprocess to smaller chunks; consider diffing smaller segments.
• Permission denied: Run the console as Administrator or adjust file permissions to allow read access.
• Corrupted system file: Run System File Checker: sfc /scannow from an elevated prompt to repair fc.exe if needed.

Related Processes