Microsoft Visual Studio

I have coded my project in DreamWeaver using ASPX. I am importing my project into MicroSoft Visual Studio. I am getting all kind of HTML errors in Visual Studio. Saying the tags are
outdated. For example:

The error says width is considered outdated, a newer construct is recommended. But no example of a new HTML tag construct is given. I am getting this on most all of the HTML tags. Can you help