Can you steer me toward a current, correct solution to a Blue screen?

Here are the specifics:

STOP: c000021a {Fatal System Error}
The Windows Logon Process system process terminated unexpectedly with a status of 0xc0000135 (0x00000000 0x00000000).
The system has been shut down.

I was removing some software and the system rebooted.

It is possible that windows update was doing something at the time.

Any suggestions of where to start?

You can reinstall the OS on top of itself using the installation media. You will not loose any data but you will have to reinstall updates and service packs.

Not sure what OS you are running. So I'm assuming you have already tried Pressing F8 during start up and selecting Last Known Good or Safe Mode.

Hope this helps.

Have you changed any RAM, gfx cards, or your PSU recently?
What were you running at the time of the BSOD?

My OS is Windows XP Pro wSP2.

I was uninstalling a couple of small programs and rebooting. However, in that process I saw something that made me think that windows update might be doing something at the time.

No new hardware lately

Can you start in safe mode? Windows may have been updating a timezone file for its datetime service... but that should have gone ahead unless you did an abrupt or hard shutdown like a plug pull.

No, it will not start in safe mode either.

What stage can you get to when booting, did you press F8 to get into safe mode?
Also how much RAM do you have in your computer?

cathe, I've looked around as I guess you have; it seems that if you cannot do an F8 at boot to get to LKGF you are pretty much stuck with doing a windows Repair [which will restore your registry, but not interfer with your apps n data].
A parallel installation as per M$ instructions [they talk about NT but that is true for XP also] would not help cos you don't know exactly [ no event log access] what the problem is that caused the stop.

Re-installing Windows seems to have worked. I am at least in, and scanning for viruses, etc. I will post again soon to let you know if everything seems ok.

Thanks for the help.

Windows reinstalled and seems to be running fine, EXCEPT that none of the patches will load from Windows Update. I tried both automatic updates and manually loading them. Tried doing one at a time. There are 81 updates that will not load.

Any suggestions?

Re-download them off the microsoft site. That might your only option with that one.

I had tried that. MS KB suggested this:

When accessing the Update site, you receive the 0x800A01AE error. Last updated : 10/21/2005 Print | Close

Problem description
A required system file is not registered correctly.

Applicable operating systems and products

Windows 2000

Windows XP

Windows Server 2003

1. Re-register the Windows Update DLL with the commands below
Click Start, click Run, type cmd, and then click OK.
Type the following commands. Press ENTER after each command.
regsvr32 wuapi.dll
regsvr32 wuaueng.dll
regsvr32 wuaueng1.dll
regsvr32 wucltui.dll
regsvr32 wups.dll
regsvr32 wups2.dll
regsvr32 wuweb.dll

Attempt to run Windows Update

And that seems to have worked.

Thanks for all your help. As long as I don't run into anything else, I think I might be close to getting this taken care of.