Compacting

I have a computer that I have never used Outlook Express on, never set it up, never opened it,, don't want to use it, that suddenly after that last Windows Update started always asking me if I want to Compact the Mail.
I don't even want to EVER OPEN Outlook Express.
What did Microsoft do during the last Update cycle that would cause this?
Is there some virus/trojan out there that has managed to hijack the Outlook Express system?