When installing the increment you must install the exact same component as was installed for SCM V13 GA release. With the SCM Client there are two different types - Full Client and Workbench Only. If you try to install Increment 2 of the wrong type of client you will get an error message like this.
If you installed SCM v13 GA release of the 32-bit Full Client, and then try to install the SCM V13 Increment 2 of the 32-bit Workbench Only client you will see something like this:
Error 2711. The specified Feature name ('<userid>') not found in Feature table
If you do the opposite, and install the SCM v13 GA release of the 32-bit Workbench Only client, and then try to install the SCM V13 Increment 2 of the 32-bit Full Client you will see something like this:
Error 2727. The directory entry '<long hexadecimal value>' does not exist in the Directory table.