I had set my SCCM 2007 R2 environment (using native mode) up for automatic client push but noticed that none of my clients have the SCCM agent installed after a few days. The log contained at c:\windows\ccmsetup\ccmsetup.log on the client showed that the installation was failing and the error messages included: WINHTTP_CALLBACK_STATUS_FLAG_CERT_CN_INVALID is set Failed [...]