Some time back i worked on one of the issues where when users login to the server they get a prompt saying that the worker process terminated unexpectedly. In the Event logs we see the following event id's

In event logs we see the following event ids getting generated.
==============

Event Type: Warning
Event Source: W3SVC
Event Category: None
Event ID: 1009
Date:*******
Time: ********
User: N/A
Computer: ******
Description:
A process serving application pool "AppPoolName" terminated unexpectedly. The process id was 'PID'. The process exit code was '0xffffffff'.

Event Type: Information
Event Source: W3SVC
Event Category: None
Event ID: 1074                                        ------------------->       AppPool recycling
Date: ********
Time: ********
User: N/A
Computer: ******
Description:
A worker process with process id of 'PID' serving application pool "AppPoolName" has requested a recycle because the worker process reached its allowed processing time limit.

Event Type: Error
Event Source: Application Error
Event Category: None
Event ID: 1001
Date: ********
Time: ********
User: N/A
Computer: ******
Description:
Fault bucket 395446657.

Event Type: Information
Event Source: Application Error
Event Category: (100)
Event ID: 1004
Date: ********
Time: ********
User: N/A
Computer: ******
Description:
Reporting queued error: faulting application w3wp.exe, version 6.0.3790.3959, faulting module webengine.dll, version 2.0.50727.210, fault address 0x00002fe7.

Event Type: Error
Event Source: .NET Runtime 2.0 Error Reporting
Event Category: None
Event ID: 1000
Date: ********
Time: ********
User: N/A
Computer: ******
Description:
Faulting application w3wp.exe, version 6.0.3790.3959, stamp 45d6968e, faulting module webengine.dll, version 2.0.50727.210, stamp 45072279, debug? 0, fault address 0x00002fe7.

Event Type: Warning
Event Source: W3SVC
Event Category: None
Event ID: 1009
Date: ********
Time: ********
User: N/A
Computer: ******
Description:
A process serving application pool "AppPoolName" terminated unexpectedly. The process id was 'PID'. The process exit code was '0xc0000005'.
 

When we look at the crash dump we see the following error.

===============================================

0:036>
Error code: (Win32) 0x3e3 (995) - The I/O operation has been aborted because of either a thread exit or an application request.

From the event log we see that the crash is happening (event id 1009) when the appPool is getting recycled (event id 1074)


Resolution
===============
Please check the following article and follow the steps acccordingly
An IIS 6.0 application pool may unexpectedly exit when a worker process shuts down or is recycled
http://support.microsoft.com/?id=918041

Disclaimer: This is a personal weblog. The opinions expressed here represent my own and not those of my employer.