SPTD.sys

sptd.sys is a driver file created by Duplex Secure Ltd. that uses its proprietary SCSI Pass Through Direct method of accessing storage devices. It has been associated with software programs like Daemon Tools, Alcohol 120%, and PowerArchiver.

Remove or Uninstall sptd.sys

Unfortunately sptd.sys sometimes conflicts with other programs and is not usually automatically uninstalled when the associated program it came with is uninstalled which can also create conflicts upon reinstallation of the software program. To uninstall and remove sptd.sys follow the directions given at the Duplex Secure website here.

IPSEC Services Error 1747: The authentication service is unknown - Fix for Windows XP

When looking at Windows XP's Event Viewer one might encounter this authentication service is unknown error.  This probably indicates that the IPSEC Services Service, which manages IP security policy and starts the ISAKMP/Oakley (IKE) and the IP security driver on the computer, is disabled and unresponsive to commands to start.

If IPSEC Services won't start and attempts to enable the service by selecting Start, Manual, or Automatic under Start → Control Panel → Administrative Tools → Services do not work, the reason may be an uninstalled or missing Client for Microsoft Networks module and the solution may be to activate Client for Microsoft Networks.  Go to Start → Control Panel → Network Connections and select a connection or create a new one.  Select Properties. In the window under the heading "This connection uses the following items:" Client for Microsoft Networks is probably not installed.  Install it by clicking Install..., then selecting Client and clicking Add..., selecting Client for Microsoft Networks, and then OK.