So, what happens if you can no longer log in under the user that had all of your extensive Visual Studio customizations and you hadn't backed it up? (Yes, this happened to me). You can open regedit, select HKEY_USERS, go to File->Load Hive. Find the ntuser.dat file of the defunct user, load it with a key like user-old, browse to SoftwareMicrosoftVisualStudio. Export this entire key, then unload the hive (File->unload). Open the exported registry in a text editor, and replace all instances of HKEY_USERSuser-old with HKEY_CURRENT_USER. Double-click the file to add to the registry and you're all set!