The Configuration Manger 2007 SP1 Client directory has significantly increased in size from previous SMS versions.  The reason for the increase in size is because the Client directory now contains all of the necessary client prerequisites, including platform specific (i.e. IA64, x64 and x86) and language specific updates.  Depending on your environment and target client systems, many of these prerequisites are not required and do not need to be deployed in order to have a successful client upgrade or installation.

Looking at the ConfigMgr 2007 SP1 Client directory structure (located in the InstallationDirectory\Client), you will find approximately 111 MB of data comprising of 96 files and 7 folders. 

 If your environment only consists of Windows XP x86 English systems, then this can be reduced considerably.  First, I recommend making a copy of this directory so that it can be used as a Package Source for upgrading ConfigMgr 2007 RTM Clients to SP1 using Software Distribution.  You will notice that there are three directories listed for each platform architecture – i386, ia64 and x64.  Since we are only dealing with x86 (i.e. i386) systems, then we can delete ia64 directory and save 18.7 MB (7 files and 1 folder).  Also, we can delete the x64 directory and save another 20.3 MB (14 files and 1 folder).  Once again, make sure you do not delete the files and folders from the original directory.

Looking into the i386 directory, we find two subfolders: BITS20 and BITS25.  Because we do not have any Windows 2000 systems, we can delete the BITS20 folder and save 16.5 MB (24 files).  Opening the BITS25 directory, you will see multiple instances of the BITS 2.5 installation executable for Windows Server 2003 and Windows XP.  These are the different language specific installations.  We can delete all of the Windows Server 2003 files (18) and all of the non English Windows XP files (23) for a savings of 26.2 MB (41 files).  The end result of the Client directory should be 29.3 MB consisting of 10 files and 2 folders.  This results in a significant reduction from the initial 111 MB size.

In summary, the new client directory can now be used to create a Software Distribution Package for upgrading RTM clients that are in slowly connect branch offices or remote locations.  It can also be used for initial installation of clients as well.