Hi Zinnia
Welcome to Answerpool
This sounds to me like a misloaded update on the Patch Tuesday has caused a conflict in your Outlook express Program.
So how to fix? .I do not run Vista nor Outlook Express But I do know XP well but what I say will be in a slighty different order/position to XP OK
So from my XP point of view you want to open System Restore and pick a date before the Last Patch Tuesday which for this month was the 8th
the Restore Points are always Highlighted so if Monday the 7th has a restore point then start from ther if there is none work backwards to the beginning of the month then simply click on the link to start the Wizard
Do this offline And shut down any running program ...the procees will take a few minutes then the computer resets
When you start again you may find some recent installed programs and updates uninstalled...but most importantly the MS security updates have been deleted and Things are now "normal" again?
For your information the April "Patch Tuesday" date was the 10th but Its doubtful you'll have to go that far back
Dwight will be along later and He's better with these things so look out for him

I hope I have been of some help?