reference http://stackoverflow.com/a/19386617
solution 1
Find what:
1
.*help.*\r?\n
Replace with: text box empty.
Make sure the Regular expression radio button in the Search Mode area is selected. Then click Replace All and voila!
solution 2
Is also possible with Notepad++
Goto the search menu Ctrl+F and there to the “Mark” tab. Check “Bookmark line” (if there is no “Mark” tab update to the current version).
Then just enter your search term and click “Mark All”
==> All line containing the search term are bookmarked.
Now go to the Menu “Search -> Bookmark -> Remove Bookmarked lines”
origin - http://www.pipiscrew.com/?p=2124 notepad-remove-lines-containing