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.
SDET| Visual Web Developer