Auto setting ClawPDF as default printer.

[RueAnd-tech]

clawPDF aggressively sets itself as the default printer after installation in RDS / Terminal Server environment – even with Windows default printer management disabled

Environment:

• Windows Server 2022 (or 2019) RDS Session Host
• clawPDF version: [insert your exact version, e.g. 0.9.5 or check Help → About]
• Multi-user RDS / Remote Desktop Services environment
• Group Policy already has "Turn off Windows default printer management" enabled (LegacyDefaultPrinterMode = 1 in both HKCU and HKLM)
• Printers are deployed and set as default via GPO Preferences (User Configuration → Preferences → Printers → Set as default)

Problem:
After installing clawPDF on the session host (even silently or as admin), it automatically sets itself as the Windows default printer for logged-in users — overriding the GPO-configured default printer.

This happens:

• Immediately after installation
• Or on first print job to clawPDF
• Even though we have disabled "Let Windows manage my default printer"

We have tried:

• Deleting / changing HKCU\Software\clawSoft\clawPDF\PrimaryPrinter (it gets recreated as "clawPDF" during print jobs or app startup)
• Forcing HKCU\Software\Microsoft\Windows NT\CurrentVersion\Windows\Device via GPO Replace action every login
• Enabling RDS policy: "Do not set default client printer to be default printer in a session"
• Restarting Print Spooler after changes
• Monitoring registry with ProcMon – clawPDF.exe performs deletes and recreates on keys under clawSoft\clawPDF during print processing

Desired behavior:
We want clawPDF to function as a normal print-to-PDF driver without ever changing the Windows default printer. The default should remain controlled by our existing GPO printer deployment.

Questions:

1. Is there a registry key, config file, or silent install parameter to permanently disable the auto-default-printer behavior during install and print jobs?
2. Is allowDefaultPrinterSwitch (mentioned in scripting docs) supposed to prevent this? If so, where/how can it be set globally or per-install for all users in RDS?
3. Has anyone successfully prevented this in a multi-user / Terminal Server / RDS environment?
4. If this is by design, is there a recommended workaround that doesn't involve hard-coding a specific printer name in registry (since we want GPO to decide the default)?

Any help, pointers to undocumented settings, or confirmation that this is a known limitation would be greatly appreciated.

Thanks in advance!