I know you are thinking that is a crazy title because MOSS 2007 SP2 cannot be applied before WSS 3.0 SP2. Well it can be done! With the original version of MOSS 2007, one was unable to install on the Server 2008 platform without a slipstreamed install version that included at least SP1.
On a recent engagement of mine, the consultants before me had inadvertently installed MOSS 2007 on Windows Server 2008 using a slipstream install that included MOSS 2007 SP2 but not WSS 3.0 SP2. As you can well imagine, the client was experiencing a myriad of issues with this configuration.
If you simply launch the Service Pack executable file,it will automatically unpack the contents and promptly produce a message box stating, “The update is already on this system.” Instead open a command prompt, cd to the directory where the exe resides and executed the file with the /extract: switch to extract the contents of the Service Pack to a location on the Local Hard Disk. For example:
This will extract the contents of the Service Pack to C:\SP2. Navigate to C:\SP2 and note that there are three msp files. The last one, wsswwsp2.msp, is a bootstrapper for the other two and is not needed in our situation. Open the first one, stswwsp2.msp, to apply the main SP2 for WSS 3.0. Then open the second one, wssmuisp2-xx-xx.msp, to apply the language pack for your language – mine was en-us or 1033.
After those complete make sure you repeat the process for every server in the SharePoint farm and don’t forget to run the SharePoint Products and Technologies Configuration Wizard to complete the update.