You can do nearly everything in the Visual Studio IDE as a normal user, but, you need administrator permissions to complete the following tasks:

• Installing Visual Studio.
• Upgrading from a trial edition of Visual Studio.
• Installing, updating, or removing local Help content.
• Developing solutions for SharePoint 2010.
• Acquiring a developer license for Windows Store.
• Adding classic COM controls to the Toolbox.
• Installing and using add-ins that were written by using classic COM in the IDE.
• Using post-build events that register a component.
• Including a registration step when you build C++ projects.
• Debugging applications that run with elevated permissions.
• Debugging applications that a run under a different user account, such as ASP.NET websites.
• Debugging in Zone for XAML Browser Applications (XBAP).
• Using the emulator to debug cloud service projects for Windows Azure.
• Configuring a firewall for remote debugging.
• Profiling an application.
• Deploying a web application to Internet Information Services (IIS) on a local computer.
• Changing how you participate in the Visual Studio Customer Experience Program.

Reference.

User Permissions and Visual Studio

Why run Visual Studio as “Run as Administrator”?