XP SP2 trouble

Hi, I have installed XP SP2 & now my computer is telling
me that I need a password for my Outlook Express so I
cannot access it. However I don't have this set up & it
tells me that there is mine & 'general' in the
identities. I really don't like this service pack, it has
messed around with things too much. I have always kept my
computer updated, I use a firewall & antivirus, all kept
upto date. Also, since installing SP2, I keep getting
messages from my firewall about LSASS_VULNERABILITY & it
locks the internet out. (this is easily remedied, but is
very irritating when it happens every 10 mins or so). Any
insight as to what the answers are would be appreciated.