MOSS 2007: Event ID: 2424 - The update cannot be started because the content sources cannot be accessed. Fix the errors and try the update again.

For those of you who have encountered this error, know that it is quite annoying. This is the error:

This error is basically saying that there is not enough permission for the account that is trying to access the content related to "Windows SharePoint Services Help Search".

Under the Central Administration go to Operations and then Services on Server.

In Windows SharePoint Services Help Search you'll notice 2 accounts. One being the Service Account and the other being the Content Access Account. These 2 accounts are configured at the beginning of the SharePoint installation when you define the accounts that are being used. If you look at your SQL server, you'll notice that these two accounts have identical permissions (if you haven't changed anything that is).

Because this error specifically says "content sources", the account in question will be the "Content Access Account". I've gone from giving this account read access for all content databases to even giving it owner permissions as a last resort and nothing worked.

After a bit of searching on the net, I changed the Content Access Account to use the exact same account as the Service Account and it worked. No more error message.

Now, I would love to bring this to Microsoft and ask them exactly why this works as both accounts had the same permissions in the SQL server. But knowing them they'll charge me just for asking this question. Although the problem is solved, it bothers me that I don't know exactly why it is fixed using this method. The Service Account must have some extra privileges elsewhere that I am not aware of that are different from the Content Access Account. Hopefully, I will eventually come across the answer to this. But for those of you who are encountering this same problem. Make the Service Account the Content Access Account as well and all should be good.