A lot of persons are getting this, you always give this a try, I think it
something to do with permissions, ensure that you logged on with
Administrative priviledges:
a.. Open up control panel and double-click on add/remove programs.
Select Microsoft AntiSpyware
Select "Change"
On the Microsoft AntiSpyware Maintenance Wizard, click next.
On the next screen (Microsoft AntiSpyware Maintenance Wizard) select Update
Microsoft AntiSpyware and click next.
Select Install
Let the product update.
Click Finish.
Andre