From MSDN: http://msdn.microsoft.com/en-us/library/e2h7fzkw%28VS.100%29.aspx#uninstalling

To uninstall Visual Studio 2010

To uninstall Visual Studio, download and run the Microsoft Visual Studio 2010 Uninstall Utility (or download from this page). By default, this removes Visual Studio and supporting components, but does not remove components that are shared with other applications on the computer. To also remove shared components, run the uninstall utility with the /full switch. To also remove the .NET Framework 4, use the netfx switch. Uninstalling shared components or .NET Framework 4 may break earlier versions of Visual Studio or other applications that depend on.

If you cannot uninstall Visual Studio by using the uninstall utility, you can perform a manual uninstall by removing Visual Studio and then removing related components.

To manually uninstall Visual Studio 2010

1. In the Control Panel, open the utility for uninstalling a program, for example, in Windows 7, open Uninstall a program.
2. Remove all instances of Visual Studio 2010 products.
3. Uninstall any supporting products, in the following order. In non-English installations, you must also remove language packs for some of the listed products. You do not have to reboot until after you have removed the last package on the list.
   1. Microsoft Visual Studio 2010 ADO.NET Entity Framework Tools
   2. Microsoft SQL Server 2008 R2 Transact-SQL Language Service
   3. Microsoft SQL Server 2008 R2 Data-Tier Application Project
   4. Microsoft SQL Server 2008 R2 Data-Tier Application Framework
   5. Microsoft Sync Framework SDK v1.0 SP1
   6. Microsoft Sync Framework Services v1.0 SP1
   7. Microsoft Sync Framework Runtime v1.0 SP1
   8. Microsoft Silverlight 3 SDK
   9. Microsoft ASP.NET MVC 2
   10. Microsoft ASP.NET MVC 2 – Visual Studio 2010 Tools
   11. Microsoft .NET Framework 4 Multi-Targeting Pack
   12. Microsoft TFS Object Model
   13. Microsoft Visual F# 2.0 Runtime
   14. Microsoft Visual Studio x64 Prerequisites