Had a problem with sccm 2012 client installation today,it keeps generating error code 1638 from ccmsetup.log . File C:\Windows\ccmsetup\{181D79D7-1115-4D96-8E9B-5833DF92FBB4}\client.msi installation failed. Error text: ExitCode: 1638 Use ctrl+L to find the error code description for 1638, it says “Another version of this product is already installed. Installation of this version cannot continue. To configure or remove…