Problems installing Vista updates.....

Guys,

I have many pop ups in the bottom rand corner of my screen telling me that I have updates ready to install.

Right now I have as many as 46 updates to install but the trouble is only 1 or 2 seem to install?

When I check the updates history virtually all the updates have fail bar the odd 1 or 2 which are successfull.

I usually use the left hand close down button (the one which installs the updates when shutting down) and when I re-start my PC it configures for a long time but hardly updates anything!!

Easy there an expanation for this perhaps or am I doing something wrong!?

Thanks in advance guys.
Nik