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lsass.exe system error


FPCH New Member
Feb 19, 2007
hi, this is the message that comes up when i try to turn on the pc, it's a philips mt2400 windows xp media centre edition, can anyone help, i have no reboot disc


FPCH Member
Jan 21, 2006
Telford, UK
The LSASS process manages user logins and as such is a common target for malware infections on Windows. There is a strong possibility that this is the Sasser worm. You are running an old version of Windows that needs to be updated with Service Pack 2.

If you have important files and data that you would like to keep, your best solution is to perform what is called an "in-place upgrade", also known as a repair install. The disadvantage of this is that some malicious files created by the Sasser worm (and any other infections you might have) may remain on your hard disk.

The following two articles from Microsoft explain how to perform a clean installation (by booting from the Windows XP CD) and how to perform a repair install, respectively:

How to install or upgrade to Windows XP
How to perform an in-place upgrade (reinstallation) of Windows XP

If you decide to do a repair install, your user account folder will remain in the place it originally was. So, for example, C:\Documents and Settings\yosser. In that folder there will be your "My Documents", "Desktop" and other data folders that you originally had. If you decide to perform a repair install, disconnect your computer from the Internet. Once you have finished installing Windows, update it to Service Pack 2 and follow all of the steps and advice on this website provided by Microsoft.

If you decide to do a clean install, the updating and protection steps that I just mentioned still apply. The caveat is that to do either of these two types of reinstallation, you are required to have a Windows XP CD at hand. It varies from manufacturer to manufacturer as to whether they supply you with this disc. Otherwise, you may be able to recover your machine by running the built-in recovery routine. Check the user manual that came with your computer.


FPCH New Member
Jul 2, 2007
I made the horrible mistake of deleting the file lsass.exe from the system32 folder. The start of the problem was a nasty virus. Now my Window XP, service pack 1, will not show the login screen. Is there any way to recover the file or can I boot into dos and replace it with another lsass.exe from another computer?


FPCH Member
Jun 29, 2007
PC Experience
Operating System
do you have an xp cd,
If so boot from it (make sure your bios is set to boot from cd).
when prompted enter recovery console.
when in there it will ask you to select which account to log on to.
choose which one.
it may ask for your password for the admin account,,this is usually blank.
when in there type in withut the qoutes (d: being the drive the cd is in)
"copy d:\i386\lsass.ex_ c:\windows\system32
if you are prompted to overwrite click yes....
try that.
remember to put a space between lsass.ex_ and c:\windows
i hope that works.......
i know it has worked on numerous machine i have had to repair.