Help With BSOD c000021a please...

Hello, I’ve been having some trouble with my laptop, hopefully someone here has the time and patience to read this and give me some advice on how to fix it, I’ll provide as much info as I can.

Laptop is Lenovo w520 ( got it around 2011) running Windows 7 Pro 64 bit, 6 gb of Ram ( 2 sticks, 2gb and 4gb), 500 Hitachi HDD, Nvidia Quadro 1000m / Intel HD Graphics.

To make the long story short couple days ago I booted my pc and bam BSOD:

STOP: c000021a [Fatal System Error]
The initial session process or system proc…
tus of 0x00000000 (0xc0000001 0x00010a58).
The System has been shut down.

…before this I just checked my email and browsed the web, did not install programs, clicked on suspicious links or downloaded any updated that I know of.

Things I’ve tried:

  1. Safemode, not working.

  2. Last Known Good configuration, no luck there.

  3. System Repair and Windows Restore Point, nothing.

  4. Ran Windows Memory Diagnostic Tool and Memtest+86, tested each stick in each slot and found out that the 4 gb stick of ram was showing some errors, so Im using the 2gb stick atm which I think should be enough to run the pc just fine.

After reading many threads on a possible fix I found out about Hirens Boot Cd and I ran almost every possible test on RAM, HDD and some of the basic antivirus/malware tools it comes with although some of them can’t get em to work like combo fix, others like the rootkit tools I have no idea how to use, but so far all of the tests that I’ve done tell me that everything is fine, will run them again if anyone here request a specific test.

Last test that I performed was FRST64 that I found on this related thread http://forum.avast.com/index.php?topic=120531.0. I’ll include the txt if someone here can have a look at it.

I’d like to keep the option of buying new hardware like RAM and reformating my HDD as a last resort.

Thanks in advance.

This error occurs when a user-mode subsystem, such as WinLogon or the Client Server Run-Time Subsystem (CSRSS), has been fatally compromised and security can no longer be guaranteed. In response, the operating system switches to kernel mode. Microsoft Windows cannot run without WinLogon or CSRSS
If you are lucky, a in-place-repair will solve it. If not, restore the system to factury default or perform a clean install of the os.

Thanks for the quick response, but like I said Id like to keep that as my last resort since I have a lot of data that I would have to backup + the cost of the extra ram + the cost of the repair…

is it possible that it might be a zero access infection or some sort of malware or file that I need to move/delete or something?

If a in-place-repair works, you will not loose any data.
But always make a backup.
You should be able to do that with a live-cd/dvd.

Download attached fixlist.txt and save it to your USB flashdrive as fixlist.txt

Boot into Recovery Environment

Start FRST in a similar manner to when you ran a scan earlier, but this time when it opens …

[*] Press the Fix button once and wait.
[*] FRST will process fixlist.txt
[*] When finished, it will produce a log fixlog.txt on your USB flashdrive.

Exit out of Recovery Environment and post me the log please.

Try to boot Windows normally…

UPDATE: MY SYSTEM IS BACK
my hope to resolve this issue was quickly fading and it seemed like the last option would be the only solution, take it to the repair shop and possibly pay hundreds of dollars for a fix that was very simple.

My solution was going back a few steps, exactly to the system restore option in the recovery menu, I saw 2 restore points :

1/22/2014 Automatic Restore Point
1/15/2014 Avast antivirus system restore point

I tried going back to those but the next screen said that I had to enable system protection on my drive and couldn’t do anything after this, so after some more research I found this thread and my solution was on that exact same page

http://www.sevenforums.com/backup-restore/274204-enable-system-protection-local-disk-c-cmd-3.html

just typed the exact same thing in the command prompt on the recovery console and that apparently fixed the registry on my system and is back from a BSOD holy shenanigans, slow because I only have 2 gigs of ram but its back.

Im curious about the fixlist test and see if that can also give me a solution if this happens again, but hopefully the problem is gone forever, its late and have to get some sleep but thanks anyway for the quick responses in here.

Hopefully this can help someone out there that is having the same problem.