I was changing some of my VS 2010 tools –> options… messed up something – debugging no longer worked.  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 follow the below instructions:

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, click Reset all settings and then click Next.

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

   —or—

   If you want to delete your current settings combination, choose No, just reset settings, overwriting my current settings, and then click Next. 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.  Now you are back to where you started.