My Windows Update keeps telling me that I have 5 (put your random number here) important updates to install. However, when I click on them, the list that pops up is empty. I can still install the updates, but I cannot see and of course also not decide which updates are going to be installed.
I have found that Microsoft Support are very good at these type of problems which go to the core of their operating system. I would email them, or even phone them if they supply a freephone number for your area.
I have to admit that such calls go one of two ways, you are either stunned how easy and efficient they are, or it's a nightmare of holding redirecting, in which case I would just hang up.
This can occur from a corruption in the Cryptographic service database log
The following steps will delete the log, which will be automatically rebuilt as needed
After every is working again, go ahead and delete the edb.tst file