Alright, I recently started get this REALLY annoying Norton Anti-virus warning for the file called C:\\WINDOWS\lsass.exe and saying how it's supposedly a Trojan horse threat. Weird thing is that every time I scan it with Norton to clean or delete it, it won't do it. Well, now I find out that it's an attachment for the Windows Security updates and now Norton won't leave me alone about it! What's going on?!
"...annoying Norton Anti-virus..." there's your problem right there. You might wanna try using a different anti-virus program (I use Avast), and if you're gonna be doing anything involving the System precesses(like Isass.exe), do it in Safe Mode.