Hi miamibob,
Thanks for your question. All the descriptions are in my first post, which I cannot find on the board. When I posted it, there was notice that it would need to be reviewed by administrators or moderators.
It's a fairly long post and I'll see if I have time later to create or shorter version if the original is still not up.
Now to the technical part. The signatures themselves cannot be disabled, however the checking that W7 in a default install does (verifying the signatures) can be disabled. When that checking is disabled, the OS is running in "Test Mode". In that case, a notice to that effect appears in the bottom right corner of the screen (unless the admin of the system chose to do away with the notice).
So, if the system is in Test Mode, the manual install of non-signed files is possible. Big CAUTION here, as a system safety feature is now disabled. In the original post I indicated that I take no responsibility for the consequences of the use or the attempted use of this method and I want to restate that here too. The Winsdows Update does not seem to be affected by the Test Mode and it seems to check for valid signature no matter what the mode. And that is fair.
Note that the AV/Firewall may still complain or silently abort the manual install even in Test Mode. That would depend on the particular software. I had to temporarily disable mine. Another big CAUTION here.
Now, how to get into Test Mode? I used a third part free utility (another big CAUTION). Google for DSEO. It worked fine for me. Needs to run as admin and low UAC.
Hope this helps.
