If you have had some issue with installing SP1 client on computer with the error message
Installation error 0x800b0101: System Center 2012 Configuration Manager Service Pack 1 client
Couldn’t verify ‘C:WINDOWSccmsetupMicrosoftPolicyPlatformSetup.msi’ authenticode signature. Return code 0x800b0101
There is now a hotfix available from Microsoft to download à
http://bit.ly/13utSpQ