DirectX, Windows update, ActiveX...

Urghh wasting my life away trying to download DirectX. I go through the 
validation process and i get the go ahead to download it. When i start to 
install it, it comes up with an error saying something about
'cryptographic 
services' and that a cabinet file cannot be trusted. So 'Microsoft' can
even 
trust there own software? Anyone else having these problems?

My windows update on my system is also grayed out. It will not let me
change 
the options so that my computer can receive updates. 

As ActiveX, well...Whenever i go to update my computer manually, (without 
the 'USELESS' Windows Update) It says that my security settings are 
prohibiting it. I have tried everything! Putting the security settings
down 
to low, and enabling all ActiveX even possibly dangerous. Still, no hope.
My 
father will never get round to fixing it for me, so i am subjected to
using 
my knowledge to try and fix. I'm 14 X=]

Any help would be greatly appreciated. 

Toodles..x