http://www.sqlservercentral.com/blogs/dknight/2009/07/06/recovering-missing-templates-in-visual-studio/

Recovering Missing Templates in Visual Studio

2009/07/06

Recently I decided to expand my coding knowledge and picked up a Visual Basic book.  I’ve been working in this new book for about two weeks when I opened Visual Studio this morning and all my VB templates had disappeared.  Of course, it turned out to be a common problem and immediately found the answer so I thought I’d just pass it along. 

• Make sure that Visual Studio is not open and bring up a command prompt
• Navigate to the Visual Studio executable (devenv.exe) is.  In my case C:\Program Files (x86)\Microsoft Visual Studio 9.0\Common7\IDE\.  Could vary depending on the version of VS and processer you have.
• Type devenv.exe/installvstemplates and this will reinstall your templates for you!