Certificate problems

I presume I have been hit by a virus or other disableing attack. I try to install Windows Vista sp1 and get the same failure time and again, even after attempting to install the certificate. I get error 800B0109. When I try to install Mcaffee, I get unable to setup frame window error, and have tried updating the file supplied by Mcaffee. It seems that everything I attempt is blocked by this certificate error. Anyone else run into such a crippling event? If so, were you able to overcome it? I am running (crawling with) Vista Ultimate. Thanks in advance for any help.

That error code means "A certification chain processed correctly, but terminated in a root certificate which isn't trusted by the trust provider."

I think you need the latest Windows Update Agent. Try the MS website http://www.microsoft.com/en/us/default.aspx

Good Luck