Try uninstall and reinstalling the software to see if it fixes the problem
and ensure you are logged onto the computer as an administrator. If that
does not work, give this a try:
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.