Extended Search & Replace
To find files by name, type a file mask and click Find Files. To find text-based files containing particular text, enter it in the Find textbox; you can use case-sensitive searching, and even use wildcard characters * and ?. The search results will be shown below (you can stop the search at any time if you see the file you were looking for). If you were searching for text, the number of instances of that text will also be shown.
You can do several things with the search results. They work just like a Windows folder, so you can right click them to use their context menu (and even use ShellToys tools on them), drag files to a folder or the desktop or copy or move them, double-click a file to open it, or drag it into an application.
Most importantly, you can replace all the instances of the searched text with something different. Remove the checkmarks beside any files you don't want to alter, type replacement text into the Replace With box and click Replace Text. You can use wildcards in the replacement text, so you could set the text boxes like this:
Find: <img *border="1to replace any HTML image tags containing a BORDER="1" attribute with BORDER="0", regardless of where the 'border' attribute appears in the different tags.
Replace with: <img *border="0