You may receive an error "Could not load type 'System.Security.Authentication.ExtendedProtection.ExtendedProtectionPolicy'"  after you install the update KB976769v2. WCF service may stop working also.
From the logs, we saw that one of the features containing System.dll is in the “Advertised” state, which might be the reason why the patch did not apply properly.

In order to resolve this issue you may run the repair command

1. msiexec /i {C09FB3CD-3D0C-3F2D-899A-6A1D67F2073F} /l*v %temp%\repair.log REINSTALLMODE=omus ADDLOCAL=URTM_STD_ENU_X86_IXP

2. Then see if this fixes the problem.

3. If not, reinstall Kb982168 and check if the problem is resolved.

N.B.  {C09FB3CD-3D0C-3F2D-899A-6A1D67F2073F} is the product code for .NET Framework 2.0 SP2