I first discussed the Windows Server 2003 Software Restriction Policies in tip 8048.

If you created a local policy at Computer Configuration / Windows Settings / Security Settings / Software Restriction Policies / Trusted Publishers, you may receive one of the subject errors when you try to install a program or update.

To resolve this problem:

1. Open a CMD.EXE window.

2. Type the following command and press Enter:

reg DELETE "HKLM\Policies\Microsoft\SystemCertificates\TrustedPublisher\Safer" /F