SCCM 2007 - preinst.exe /syncchild failure - sitecode is unknown

Problem:

When trying to sync your parent site with a child site in SCCM 2007 you run the following command:

preinst.exe /syncchild <sitecode>

Unfortunately preinst.exe kicks this back:

<sitecode> is unknown

Resolution:

Although chances are you have full admin rights with SCCM, chances are this is determined by security group membership and is not explicitly defined. For some unknown reason, in order to get the command to work you need to grant your user account explicit rights to the Class of SITE. To do this, open up the SCCM Admin Console and....

• Drop down the Security Rights Box and 
• Filter on the word "site"
• Click on "New" 
• Class security right
• Grant your user account full rights to the SITE class:

Now when you run the command you should be met with a more successful message: