Hotmail users...

[[TC]»Elmo«]

MSSE (on W7 at least) is actually quite comparable to much of the free AV software now.
Yes, it recently flagged Chrome (or something like that, I forget exactly) as malicious and removed it, but the paid versions of Norton, AVG and McAffee (twice) have flagged important system files as malicious and broken Windows as a result.

As Nitros said, if you can't use IE9, don't use IE at all.
And remember, if you have XP, you only have just over 2 years left (of your currently 11 year old OS) before support runs out and it becomes a virus ridden hell hole.

Oh, and make sure you keep your PDF reader and Flash up to date, as that's how nearly all drive by malware gets on your system.