ias service error 0x80004015:The class is Configured to run as a security ID diffrent from the caller

I recently had the same on an Win XP x64. The way I solved it was to delete the security descriptors from the registry for the IASJet service to force it to apply default ones. Export and then delete the following keys (do export first, just in case):

• HKEY_LOCAL_MACHINE\SOFTWARE\Classes\AppID\{A5CEB593-CCC3-486B-AB91-9C5C5ED4C9E1}
• HKEY_LOCAL_MACHINE\\SYSTEM\CurrentControlSet\Services\IASJet\Security
  

Start the "IAS Jet Database Access" service and then the RRAS service.
It should now work.
Additionally, you might also want to make RRAS dependent on IASJet so it starts the IASJet service before it starts itself. Otherwise it may fail to start with the 7024 error in the eventlog, saying
"The Routing and Remote Access service terminated with service-specific error 340 (0x154)."
Event Type: Error
Event Source: Service Control Manager
Event Category: None
Event ID: 7024
Description:
The Routing and Remote Access service terminated with service-specific
error 340 (0x154).
Just edit the registry for the RemoteAccess service at HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RemoteAccess and add "IASJet" to the list of DependOnService value (note that the services need to be separated by new lines, not spaces).