Im having some BSOD's errors and I just downloaded a program called "WhoCrashed".
This is his analysis:

On Sun 25/09/2011 15:52:20 GMT your computer crashed
crash dump file: C:\Windows\Minidump\092511-14617-01.dmp
This was probably caused by the following module: ks.sys (ks+0x1A15A)
Bugcheck code: 0x3B (0xC0000005, 0xFFFFF88002C7F15A, 0xFFFFF88008C39E10, 0x0)
file path: C:\Windows\system32\drivers\ks.sys
product: Microsoft® Windows® Operating System
company: Microsoft Corporation
description: Kernel CSA Library
Bug check description: This indicates that an exception happened while executing a routine that transitions from non-privileged code to privileged code.
This appears to be a typical software driver bug and is not likely to be caused by a hardware problem.
The crash took place in a standard Microsoft module. Your system configuration may be incorrect. Possibly this problem is caused by another driver on your system which cannot be identified at this time.

I really dont understand what the error is, my drivers are already up to date.
My OS is windows 7 x64.
I thank you in advance for your answers!

ks.sys is a windows system file ,i would try goint to start/type into the search, CMD ,when the command prompts icon comes up ,right click qon it and chose run as admin, in the cmd promt ,type with out the ", "sfc /scannow" note the space between the c and / ,it may or may not as for the windows disk ,it will replace missing or corrupt windows system files .
if no joy from that try ,from the same prompt "chkdsk /r" again without the ""

"sfc /scannow" -> no errors
"chkdsk /r" -> I did it, took me a night to finished and finally I couldnt had any document. When it was finished it just switch on Windows.
I checked a bit on google and its supposed to repair the DD if I'm not wrong.
Is there a document somewhere that explain what happened during the test?

Hmmm, i think i get it -> Pannel, administration tools, event viewer, windows, App and click on last "winlogon" event.

"The Winlogon notification subscriber <SessionEnv> was unavailable to handle a notification event."
Hmmm What does it mean? :/