C#.net performance

Question

I would like to know how to speed up the new version of a C#.net 2008 desktop application. The old version of the C#.net 2008 dektop application ran extremely fast.
Is there some kind of .net tool I can use to see where the bottle necks are located at?
The following occurred in the new version of the application:
1, Basically the production database will be changigng within a month. The new version of the C#.net 2008 will be pointing to the new database.
2. The same windows form application is being used.
3. Only 1 of 15 project files were changed were mainly. Four supporting project files were changed. One of the 4 supporting project files is only data adapters. The data adapter project file is shared by all the project files.
4. The data adapter project file orginally used .net remoting to pass data to another server. However, I just turned off the .net remoting in the main config file. I did not remove any of the actual .net remoting code.
5. In the data adapter proejct file, I changed the files by modifying the .xsd files. The .xsd files are all connected by using linq.