Internet Explorer 9?
If so, and if it is being offered via "Windows Updates" then yes, it is safe to allow the upgrade.
Mark
I have MS Windows 7, I am constantly being asked to update to a newer version? Currently I think they are on 9. It is free but should I. aren't there errors whenever a newer version comes out?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic