Question : "LSASS.exe bad" "The application or DLL c:\windows\system32\LSASRV<wbr />.dll is not a valid windows image"

"LSASS.exe bad" "The application or DLL c:\windows\system32\LSASRV.dll is not a valid windows image"  This is the error I get when I try to reboot my computer. After I get this error, I have to kill the power to get the compture to reboot. I have XPSP2 installed. I have tried "Last known good configuration", "Safe mode" and I keep getting the same message. Now I have added to my problems. I reinstalled XP home so that I could get back on my computer. First, how can I fix the problem? Second, how do I recover my old files?

Answer : "LSASS.exe bad" "The application or DLL c:\windows\system32\LSASRV<wbr />.dll is not a valid windows image"

Here is a similar previously answered question:

http://www.experts-exchange.com/Operating_Systems/WinXP/Q_21440485.html

The answer given there was to do an XP repair install.  To perform an XP repair:

http://www.microsoft.com/WindowsXP/expertzone/tips/dougknox/doug92.asp

Configure your computer to start from the CD-ROM drive. Then insert your Windows XP Setup CD, and restart your computer.

When the Press any key to boot from CD message is displayed on your screen, press a key to start your computer from the Windows XP CD.
Press ENTER when you see the message To setup Windows XP now, and then press ENTER displayed on the Welcome to Setup screen.
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Do not choose the option to press R to use the Recovery Console.
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In the Windows XP Licensing Agreement, press F8 to agree to the license agreement.
Make sure that your current installation of Windows XP is selected in the box, and then press R to repair Windows XP.
Follow the instructions on the screen to complete Setup.

After you perform an in-place upgrade or repair installation, you must reinstall all updates to Windows.
Here are a couple of Microsoft Knowledge Base articles you should read which concern possible data loss when you reinstall/repair XP:

http://support.microsoft.com/default.aspx?scid=kb;EN-US;312369
You May Lose Data or Program Settings After Reinstalling, Repairing, or Upgrading Windows XP

http://support.microsoft.com/default.aspx?scid=kb;EN-US;312368
Data Loss May Occur After Reinstalling, Repairing, or Upgrading Windows XP
 
Note that, from the above articles, the problem of data loss if your Windows XP was installed by the OEM (Original Equipment Manufacturer) has been corrected if your Windows XP has Service Pack 1 installed.