Microsoft small business knowledge base

Article ID: 286562 - Last Review: January 12, 2015 - Revision: 4.0

This article has been archived. It is offered "as is" and will no longer be updated.


After you install the free version of Pretty Good Privacy version 7.03, you may be unable to browse the Internet or connect to an IP-based network. When you try to establish a Dial-Up Networking or RAS connection, you may receive the following error message:
Unable to Negotiate Connection
PGP Error
Cannot establish connection with the PGP SDK service.
When you try to start PGPTray and PGPKey, you may receive the following error message:
Launching PGPDisk:
The PGPDisk application could not start because: "PFLError #-11939."


This issue can occur because Pretty Good Privacy 7.03 is not compatible with Microsoft Windows XP.


To resolve this issue, reset TCP/IP in Windows XP. For more information about how to reset TCP/IP in Windows XP, click the following article number to view the article in the Microsoft Knowledge Base:
299357  ( ) How to reset Internet Protocol (TCP/IP) in Windows XP
If resetting TCP/IP does not resolve this problem, run System Restore. To run System Restore, follow these steps:
  1. Click Start, point to All Programs, point to Accessories, point to System Tools, and then click System Restore
  2. Click Restore my computer to an earlier time, and then click Next.
  3. Choose a time and date that is earlier than the date when you installed Pretty Good Privacy 7.03, and then click Next.


This behavior is by design.

More information

Note that if you uninstall Pretty Good Privacy 7.03, the issue is not resolved because the program uninstalls the TCP/IP stack, and the TCP/IP stack does not support manual reinstallation.

Applies to
  • Microsoft Windows XP Home Edition
  • Microsoft Windows XP Professional
kbnosurvey kbarchive kb3rdparty kbenv kberrmsg kbnetwork kbnofix kbprb KB286562
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