Select the lines you want to be commented in your ASPX, HTML, web config file etc  and click on the Comment/ Uncomment icon in Toolbar.

The comment icon looks like this:

The icon for uncomment looks like:

Alternatively you can use  Keyboard shortcut Ctrl+K Ctrl+C to comment and use Ctrl+K Ctrl+U to uncomment.

Comments in ASPX page…

Comment in HTML page…

Comment in script blocks…

This shortcut is available under Edit Menu->Advance –>Comment Selection /Uncomment Selection.

Enjoy!

Reshmi Mangalore

SDET| Visual Web Developer