As on the same PC you were able update yesterday, I have to assume that your PC is setup correctly and you have SQL Server Native Client installed.
Second most common reason for this error - when you are running some firewall on your PC, strange thing is that in such case I have to assume you had firewall yesterday and it worked.
I had users reported same issue, and then reported back that they had this issue when they run VPN on their PC. Maybe that is your case?
If you still experience this issue, please let me know, I'll post what you should do next.