Recently I upgraded Vista Home to Ultimate. I could not get the context menu back. I thought I was going crazy trying to get it back. I uninstalled and reinstalled many a time trying to get it back. I still couldn’t get TortoiseSVN to show up. So I uninstalled and started a rampage through the registry to find what I needed to remove. I came across this key:
It had an entry for Context Menus (which I had modified). I backed the key up and deleted it. Then re-installed TortoiseSVN and rebooted. And viola! It works! That’s totally money! YMMV, but I thought I would share if you find yourself in the same boat as me.