How to Reset Visual Studio 2010 Settings to change default language environment e.g. C# to VB

You can reset the integrated development environment (IDE) to a previous state using the Import and Export Settings
wizard. All settings and categories are applied by default; if you want to specify which settings to change, use the option
Import selected environment settings.

To reset your settings

1.      On the Tools menu, click Import and Export Settings.

2.      On the Welcome to the Import and Export Settings Wizard page, clicks Reset all settings and then click on Next
Button.

3.      If you want to save your current settings combination, click Yes, save my current settings, specify a file name, and
then click on Next Button.

—or—

If you want to delete your current settings combination, choose No, just reset settings, overwriting my current settings,
and then click Next Button. This option does not delete default settings, which will still be available the next time you
use the wizard.

4.      In Which collection of settings do you want to reset to, select a settings collection from the list.

5.      Click Finish.

The Reset Complete page alerts you to any problems encountered during the reset.

When you run the Visual Studio then it will ask you to choose the default language environment. Now you can choose
your working language environment.