a) Click on Start and click on Control panel.
b) Go to Program and Features.
c) Scroll down to Microsoft.Net Framework 4 Client Profile, right click it.
d) It will give you a choice of Uninstall/Change, click it.
e) Then, it will give a choice to Repair it, pick Repair it. It will take about 4-10 minutes to repair and may vary.
f) When completed, go to your update center, and update it again.