splwow64.exe

Windows Spooler SubSystem (32-bit Printer Compatibility)

System ProcessSafePrinting
CPU Usage
0-4% on average; spikes during large print jobs
Memory
5-25 MB
Location
SysWOW64
Publisher
Microsoft Corporation

Quick Answer

splwow64.exe is safe. It's a legitimate Windows process that enables 32‑bit printer drivers to work with the 64‑bit Spooler when printing from 32‑bit apps.

Is it a Virus?
✔ NO - Safe
Must be located at C:\Windows\SysWOW64\SplWOW64.exe
Warning
Common during printing
SplWow64 starts on-demand; multiple printers and drivers can spawn instances
Can I Disable?
✔ YES
Disabling may affect printing; disable only if you do not print

What is splwow64.exe?

splwow64.exe is the Windows subsystem that enables 32‑bit printer drivers to communicate with the 64‑bit print spooler on 64‑bit Windows. It launches when 32‑bit applications print, or when compatibility drivers are required, and coordinates data exchange to ensure prints complete without user intervention.

SplWow64 functions as a bridge between 32‑bit printer drivers and the 64‑bit Windows Spooler, marshaling print data and calls. It runs briefly during print tasks and keeps 32‑bit apps compatible with modern printers without users needing to adjust drivers.

Quick Fact: Windows relies on SplWow64 to maintain compatibility with older printer drivers on 64-bit systems.

Types of SplWow64 Roles

Is splwow64.exe Safe?

Yes, splwow64.exe is safe when it resides in the official system path and is part of Windows.

Is splwow64.exe a Virus or Malware?

The legitimate splwow64.exe is not a virus. Malware may masquerade with similar names; verify path and signature.

How to Tell if splwow64.exe is Legitimate or Malware

  1. File Location: Must be in C:\Windows\SysWOW64\SplWOW64.exe or C:\Windows\System32\SplWOW64.exe. Other locations are suspicious.
  2. Digital Signature: Right-click the file in Explorer → Properties → Digital Signatures. Should show a Microsoft signature like "Microsoft Corporation".
  3. Resource Usage: Normal usage is minimal. Unusually high CPU/memory when idle is suspicious.
  4. Behavior: SplWow64 should run only during printing tasks or driver communication. Continuous background activity warrants a scan.

Red Flags: If splwow64.exe appears in non-standard folders (e.g., Temp, AppData), runs when not printing, lacks a valid signature, or uses persistent high resources, scan with antivirus and verify printer drivers.

Why Is splwow64.exe Running on My PC?

splwow64.exe runs when print tasks are issued that require 32-bit driver compatibility or when apps use 32-bit printing interfaces.

Reasons it's running:

Can I Disable or Remove splwow64.exe?

No, you should not disable SplWow64 if you print with 32-bit drivers; doing so can break printing. You can minimize impact by updating drivers or disabling automatic startup for non-essential printers.

How to Stop splwow64.exe

How to Uninstall SplWow64 (Not Recommended)

Common Problems: High CPU or Memory Usage

If splwow64.exe is consuming excessive resources during printing or idle periods:

Common Causes & Solutions

Quick Fixes:
1. Open Services (services.msc) and restart the Print Spooler
2. Cancel all pending print jobs in the queue
3. Update or remove unnecessary 32-bit printer drivers
4. Run a full antivirus scan to detect spoofed SplWow64
5. Check for Windows updates to ensure spooler components are current

Frequently Asked Questions

What is splwow64.exe?

SplWow64.exe is the 32‑bit printer compatibility host that lets 32‑bit printer drivers talk to the 64‑bit Windows Spooler. It's a legitimate Windows component.

Is splwow64.exe a virus?

Not if it resides in C:\Windows\SysWOW64\SplWOW64.exe or C:\Windows\System32\SplWOW64.exe and is signed by Microsoft. Malware can mimic names, so verify signature and path.

Why is splwow64.exe using CPU?

CPU usage usually spikes during active print jobs or driver installation. If it runs constantly, check for stuck jobs or outdated/misbehaving drivers.

Can I disable splwow64.exe?

Disabling is not recommended if you need 32‑bit printing. You can disable auto-start for printers you don't use, or update drivers to 64‑bit equivalents.

Where is splwow64.exe located?

Typically found at C:\Windows\SysWOW64\SplWOW64.exe or C:\Windows\System32\SplWOW64.exe depending on Windows architecture.

How can I fix printing problems related to SplWow64?

Update or reinstall 32-bit printer drivers, restart the Print Spooler service, and clear the print queue. If issues persist, run a malware scan and check Windows updates.

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