Menu: Tools -> Import and Export Settings
As you probably know, you can export just about any setting you want. Usually you will export several settings together. However, when it comes time to import settings there are two that will not get imported by default: "Command Window Aliases" and "External Tools List".
Sometimes, when importing, people will just click through the wizard and forget this is the case. For this reason, it might be a good idea to make sure you have these two settings exported by themselves as an extra copy. Then you can just import these settings as needed. Also, these are two common settings you may want to share with other people.
To do this just go to Tools -> Import and Export Settings choose to export settings:
Click Next, then deselect "All Settings" and select "Command Window Aliases" and "External Tools List":
Click Next, then decide what to call your exported settings and where to put them:
Click Finish and Close. You now have your settings exported.