Anti Spyware messes up Messenger?

I just scanned my computer. the next day i try to sign
into messenger. doesnt work. try with other account.
still wont work. try hotmail. donest work. I cannot
access the .NET network from my computer from any user at
all! Also i keep getting these weird pop ups from
Microsoft AntiSpyware Alert talking about "An Unknown
startup program Microsoft (R) Windows (R) Operating
System Reqires..." and a bunch of other that talk mainly
about my IE browser and I dunno whether to push allow or
block cause it says that its unknown but for example the
above mentioned alert pops up this when i choose block:
"Are you sure you would like to block Microsoft Windows
Operating Sysytem from you startup programs? .... Is this
supposed to mean that if i block it i wont be able to
start MS Windows OS? what is taht anyway? XP? should i?
help
(please send a copy of ur reply to dan _ shier @
hotmail.com (w/o spaces)

THanks