I have found googling any error message to be an invaluable place to start. The key, apparently is to determine if "we" are talking about Isass.exe or Lsass.exe, a capital "i" or a capital "l" ...the fomer is a trojan, and the latter is an MS file...at least that was I have read... check out these urls...
1.
Computing.Net - Isass.exe - System Error
"Lsass.exe is good - Microsoft component that runs under sertain conditions
Isass.exe is the name of a program installed by a trojan which opens up a backdoor port. One way to see the difference between lsass.exe and Isass.exe is to click on the "image name" in task manager and see if it it lists with the "L" processes or actually is an "I." Changing the default system font also allows you to see the difference between a lower case "L" and an upper case "I" easier. I was having problems with a different trojan and almost became convinced I had the bad one - I'm glad I checked some more before I deleted the good file."
Backdoor.IRC.Ratsou.B - Symantec.com
2.
lsass.exe-system error and an apparent solution...
"Russ Wanchisen...Jul 14, 2004, 08:41am EDT
Re: lsass.exe-system error
Good News everybody! After suffering from a (seemingly catastrophic) fatal: "lsass.exe - System Error, Object Name not found" boot msg, I was able to successfully recover the OS and get my PC back up & running again! (even without an XP install CD)!
Here's how I did it:
On a separate machine, I navigated over to Microsoft's website and looked into the details of creating a set of Windows XP Setup boot disks. I found all the necessary information here: (
How to obtain Windows XP Setup boot disks ). Since my home PC (the one with the lsass.exe error) was running XP Home Edition with SP1, the "winxpsp1_en_hom_bf.exe" file was appropriate for me. That program generated six (6) floppy disks which I subsequently used to boot up my XP Home machine and get into the "Microsoft Windows Recovery Console" mode as described here:
How to install and use the Recovery Console in Windows XP "Recovery Console" mode is a DOS-like mode with limited access to the Windows directory system files (it supports FAT & NTFS file formats, but file access is limited to only the "root" OS sub-folders. User data files are not accessible in "Recovery Console" mode).
OK, now that I was able to boot from the floppies (and access the OS system files), I pretty much followed all the details presented by Charlie White as described in his article "Windows XP crashed? Here's help" (quick-link here:
http://www.tunexp.com/faqs/windows_x...ed_heres_help/ ).
In summary, the instructions he provides allow you to effectively perform a manual system restore on your machine. So, now in the future, if your machine fails on boot-up, don't fret! First try to force a "manual system restore"... If all goes well, you should have your machine back up/running in no time!
Good luck!
Russ...N.B. All the details in Charlie White's article are correct except a small detail in Part 1 where you grab the original system repair files out of the "c:\windows\repair" subdirectory: Specifically, on my machine, the "c:\windows\repair\system" file was actually called "c:\windows\repair\system.bak" (note the ".bak" suffix). As such, the line where he says to
"copy C:\windows\repair\system C:\windows\system32\config\system",
should actually read:
"copy C:\windows\repair\system.bak C:\windows\system32\config\system
There are many other sites that offer up solutions...