COMMAND PROMPT TRICKS (VERY USEFULL)

create a file that will provide a complete list of files with a particular extension
follow these setps
goto start > run> type cmd

when you enter command prompt
type the following line

dir *.ext /s /b > abc.txt

This command line will create a file called abc.txt. this file will have a list of all the files in that directory and all subdirectories with the .ext extension.
You can then open up this file in any text editor and operate on it.
and also By changing the ext part, you can select different files.
For example, if you wanted to list all of the PDF documents, just type:

dir *.pdf /s /b > abc.txt