Switch off Windows Update for a particular program or feature

I'm getting really tired of unchecking the same Windows Update candidates so save hundreds of MB's of dowbloads, especially for programs I never use, that are in fact not even installed, and those I don't wish to update.

Is there any way to permanently, or until another explicit change, to turn off certain updates? There is an option called 'Hide update', but that unsettles me a bit.

Solution 1:

that are in fact not even installed

Can you list examples? As far as I know, if you're using Microsoft Update then it will recommend things like Windows Live Essentials but it will never download them automatically because they're flagged as "Optional".

Windows 7 Ultimate also shows the language packs.

Is there any way to permanently, or until another explicit change, to turn off certain updates?

Yes, as you have identified you can use 'Hide update'.