This is all very weird my friends. For some reason none of those above does not seem to work.
This time I formatted the Hard Disk and installed a fresh copy of Windows. I managed to install Office 2003 and AntiVirus software. Then I connected to the network. Weirdly, I couldn't install any software after that. Installer just not responded as before.
(I was trying to install Visual Studion .NET which where the setup files were in another Network Drive. The setup failed to install the prerequisities. Then I copied them to the local hard disk and retried - same error. )
I was talking to
tnc last day and she also described a similar situation where the computer started having Installer errors once the computer was connected to the Network.
I have no idea how this all happens. I am going to restart to Safe Mode and I have something to try. I will update this post after that.