I don't know about certificate and sign.
I'm a new user of wm and I found several of this popup trying and installing a new software.
But never of this case was a problem of certificates!
Only the 2nd step "...or one of this component cannot be found"
this is tipically for me when I install a sw that goes in Programmi folder (the italian folder, like yours Program files), but this is wrote to search in Program files folder.
So wm don't find it (for me it's necessary to create Program files folder and copy the .exe into them, and all goes fine)
maybe this can help you...
