lsass.exe not letting windows start

  joethebow 18:27 27 Nov 2006

Try to start XP SP2 in either normal or safe mode. After the initial splash screen I get a pop up window:

"lsass.exe has encountered an unexpected version number."

Close the box and the PC restarts.

Short of reinstalling windows does anyone have any ideas?

  anskyber 19:03 27 Nov 2006

It might be worth doing a scan with your security software. click here

  skidzy 19:10 27 Nov 2006

lsass.exe is a system essential process and should not be stopped.
However,this can be easily disguised as a virus.

Can you work at all on the pc either in safe mode or normal windows windows ?

If you can,i suggest you run your av in safe mode.This could be related to the Sasser virus.

click here

  bof:) 20:52 27 Nov 2006

Hi joethebow, if after doing what both anskyber and skidzy says, you are still having problems,download and run a programe called Hijackthis

click here

before you run it, make a folder on yor C:/ drive for it called somethiung similar to HJT and put it in there.

When you run it, click on 'Do a System scan and save log file'. This will generate a log which you can then copy and paste to the site below:

click here

Please read the instructions on the page heading, 'Please read this BEFORE posting to this board.'

It is important.

After reading it and making sure you have done all they suggest, post your log to the website providing all details of whats been happening when you start your pc.

Someone on the site will then help you.


  joethebow 23:19 27 Nov 2006

Like I said I can't get past the first splash screen either in Normal or Safe Mode so I can't run anything or get any log.

  joethebow 23:22 27 Nov 2006

I swear by Hijack this, won't run a PC without it but No Windows so no log.

  birdface 23:33 27 Nov 2006

How to tell the difference,click here .

  skidzy 23:44 27 Nov 2006

I am assuming you get about a minute before the system reboots.

If you can as soon as the system starts goto Start/Run and type (shutdown -a) without the brackets.

You may have about 60secs to do it.Then run your AV.

Just a shot in the dark here,can you try and change the ram or if you have two sticks swap them around using one at a time.

If you have the restore availble on a partition,you may be lucky and recover from system restore.Try tapping F11 on startup.

  Stuartli 23:54 27 Nov 2006


click here

You have to watch the difference between, for instance, an i and an l.

  Ashrich 00:06 28 Nov 2006

As Stuartli says, look for the difference between small l ( L ) or a capital i ( I ) ie. lsass or Isass .


  terryf 01:26 28 Nov 2006

For the future, if you have a second drive use True Image to make a backup of a good clean system then all you have to do is restore

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