Every time I update the K-lite Mega Codec Pack and despite un-checking
the 'restore to defaults' option, I find that the 'tweaks' I have made
to the ffdshow video and audio codecs have been deleted, forcing me to
enter them all over again. Could not an option be introduced to 'Save
modified tweaks?' early in the installation (or un-installation, since
a full un-install always seems necessary) process? This might mean
un-instaling only through the program itself, as opposed to Control
Panel, but at least it's a potential solution to an irritating gnat
(not really a bug!)

You can use the original instalation. Don't run the configuration from the install window, but choose it from the menu, right-click and choose run as administrator.

The installer enables those formats in ffdshow that you select during installation. Any tweaks you make to formats that are not shown in the installer will stay untouched.

Thanks for the answers.

@Lester: I'd like to try your suggestion, but right-click on what? It's not the K-lite icon, 'cos I've just tried it and there's no 'install' option there. Anyway, I'm permanently configured as administrator.

@asdf: I should have said that what I'm changing is the Direst Show exclusions, so that NeroVision, for example, will run. I don't think that's covered during the installation process.

This would be the "configure ffdshow audio decoder" and the "configure ffdshow video decoder". Just set the proerties of these two links to "run as administrator". When you run these from now on they'll have full admin priviledges.
I had same issue when running under Vista OS at times and this helped greatly. Vista and v7 assume standard user privileges unless the link is run as administrator.

@poprune
Are you talking about the "DirectShow control' settings? I have just tested and those settings are not reset when updating the pack. Only if you uninstall.

@Lester
You don't need to change the shortcuts. They do not need administrator privileges.

Occasionally, windows 'thinks' it needs the admin priviledge, when it doesn't. The indicator is when you set the ffdshow/directshow settings and the settings are not kept for some reason. I did this check when I was on Vista (now I'm on v7), and found this quirk. Sometimes it happens, and sometimes not.

Thanks to you both.