optional features dialog box is blank

Hi


Try the following:

1. Run from an elevated command prompt (type cmd in the start search box and when it shows in the list right click and run as administrator) then type sfc /scannow

2. http://support.microsoft.com/kb/931712


Also does Windows Update work still and find updates, you should have dailys from Windows Defender, or what was last date of the top update file?

If WU not working then try the built in Troubleshooters and info HERE on this, but basically open up Action Center > click Troubleshooting > make sure the "get the most upto date ......." box is ticked and then click View All, then choose Windows Udpate at the bottom and follow the prompts.