If you are administering SBS 2008, you might have found Sharepoint broken recently.  There have been no less than three problems and fixes out there:  SBS 2008 Update Rollup 2 (KB 960911) Installation Failure, Companyweb Inaccessible After Sharepoint 3.0 Service Pack 2, Files in Companyweb are Opening Read-Only After SBS 2008 UR2, and Event 2436 for SharePoint Services 3 Search.

Sharepoint broke on my personal SBS box.  In my case the Update Rollup was applied properly so far as I knew, but Companyweb gave 404 errors when I tried opening it.  Not only that, I was getting multiple event 2436 errors in my application log every five minutes.

To fix the 404 errors, I manually reinstalled the Sharepoint 3.0 Service Pack 2 file.  I got the idea from a posting from someone who tried to install Sharepoint 3.0 SP1 and broke it.  My procedure is the same though the files involved are different:

1. Download the x64 version of the Sharepoint service pack.
2. On the server, run the service pack with the /extract option and extract the files to a directory of your choice: 

wssv3sp2-kb953338-x64-fullfile-en-us.exe /extract

3. In the directory you just made, there’ll be three MSP files:

   stswwsp2.msp                                                              
   wssmuisp2-en-us.msp                                                       
   wsswwsp2.msp                                                              
   

4. In an elevated PowerShell prompt, cd to the directory and invoke each of the files one at a time:

   invoke-instance stswwsp2.msp                                                              
   invoke-instance wssmuisp2-en-us.msp                                                       
   invoke-instance wsswwsp2.msp

5. Note that it might take a long while to patch and the process may be stuck at times.  This is normal. 

Check Companyweb from the server.  If it works, continue applying the steps listed in each of the linked articles, if you haven’t done so already.  In my case I applied Event 2436 for SharePoint Services 3 Search and Files in Companyweb are Opening Read-Only After SBS 2008 UR2 and my Companyweb is now working.

I’m not sure what caused the 2436 errors but if you are troubleshooting Sharepoint on SBS 2008 you should follow all the steps in all four articles to determine your problem.  Don’t follow any diagnostics you may see for older versions of Sharepoint.