
Hey Mal,
I'm back. I've read through all of your threads, and I am very upset to see how many of your posts went unanswered during the summer months. My most sincere apologies, and you have my word that it will not happen again.
Regarding the many issues that have come up with your laptop, it all points to malware related problems. At this time, the main thing is to get your lsass.exe file back so we can figure out what is corrupting it.
Since you have the XP CD, and since it is the copy that was installed on your laptop, the Repair installation is the smartest way to go. It will not affect your personal files, and you will not have to reinstall all of your programs the way you did when you did a full installation. Put the XP CD in the drive, and boot up the laptop. When prompted hit any key to boot up from the CD.
At the first screen hit Enter, then your F8 key to accept the license information, then at the next screen, hit R to begin the repair installation. Once it has finished, it will reboot your PC, and you should be able to get in. (The process takes about 10 minutes or so).
Please post back immediately, because I want you to run some scans on your laptop to determine what is causing this problem.
Looking forward to your reply,
TTFN
LGW