Many problems simultaneoulsly, but I am posting them separately (not to increase the number of posts, but for my convenience to get the replies classified). This one is for Windows posted here, otrhers to be posted in Open Source. Sorry for the long preamble. I have already reported that all of a sudden my working Windows XP Home got deactivated. In the Boot.INI file, the default is also shown as partition2 where I had XP Home, but when I selected this (or left any selection), I got the message 'hal.dll file missing, please reinstall windows'. And when I selected XP Home, I got the 'Please activate' sort of message. Anyway, today I reactivated it (after managing with pirated XP Professional that I was forced to use) , but no sooner I went on line (FireFox/Opera). the system shut down giving the message that there was some error with 'lsass.exe' What might be this error? This happened twice today. This lsass.exe is also listed in services of Task manager. What is this, and is the error an indication of virus? And also let me add (at NO. 2 here itself) that: In Win XP Professionsl, for the last 4-5 days, internet is never accessible with any other browser except IE, Opera and FireFox gave the message that they could not connect to the sites I selected!!