do a search on the error message. It usually means that the electronic signature can't be found on Microsoft's database. You may also have to contact Microsoft's tech support people through email. But when this stuff happens to me I just usually take a DEEP breath and press <ignore> with my eyes closed <grin>.
and life goes on...
I recently bought a game that requires a better version of DirectX than what I already have, so I download DirectX 9.0c from the Microsoft website, but when I try to install it, an error message pops up and says "A cabinet file necessary for installation cannot be trusted." I have no clue how to fix this and the so-called help sections about DirectX at microsoft.com really don't help at all. Please help, I don't want $50 to go to waste.