CorelDRAW X5 entire suite freezes on start up

Help please!

Entire Corel suite freezes on start up - I cannot do anything. Reinstalling also does not work - suddenly buttons on the installer dissapeared - there is no text on them and when I click them nothing happens. 

A week ago I have installed service pack 3 and everything worked fine. It has all gone wrong again. And installation of the latest patches does not help anymore.

I am running Windows 7 64-bit and I've got a feeling that is must have something to do with system updates. 

Please help, my production machine is completely out of action and I am completely stuck!