The driver may not support isolation, or the isolation setting is incorrectly configured.
Ensure that the driver is properly installed and that the Print Spooler service is running. You may need to set the driver explicitly to run in the isolated host (see below). 7. Configuring Print Isolation: Registry and Group Policy You, as an administrator, can control whether a specific driver runs in printisolationhost.exe or directly inside spoolsv.exe . Driver Isolation Levels There are three possible settings per driver: printisolationhost exe
| Level | Behavior | |-------|----------| | | Driver runs inside spoolsv.exe (no isolation) – less stable but compatible with old drivers. | | Shared (default for most) | Multiple print queues can share the same isolated host process. | | Isolated | Each print queue gets its own dedicated printisolationhost.exe – maximum stability but uses more resources. | How to Change Isolation for a Driver Method 1: PowerShell (Recommended) The driver may not support isolation, or the
Navigate to:
HKLM\SYSTEM\CurrentControlSet\Control\Print Create DWORD: EnableIsolatedDrivers = 0 But this is a troubleshooting step only, not a permanent configuration. Modern Windows versions ignore this setting if drivers explicitly request isolation. | | Shared (default for most) | Multiple
C:\Windows\System32\printisolationhost.exe On 64-bit systems, you will find it in SysWOW64 . That is an immediate red flag. Key Properties of the Genuine File | Attribute | Value | |-----------|-------| | File size (Windows 11 22H2) | ~18–20 KB (very small) | | Description | "Print Isolator Host" | | Original name | printisolationhost.exe | | Copyright | Microsoft Corporation | | Signed by | Microsoft Windows Publisher (Digital signature valid) | | Typical user | SYSTEM, LOCAL SERVICE, or NETWORK SERVICE |