Text files created on Microsoft Windows usually use a combination of Carriage-Return and New-Line (CR-LF or \r\n) to separate lines.
When such text files are opened in Windows using Vim (usually in the Unix mode), the Carriage-Return’s will show up in the file as ^M (CTRL-M) and can be annoying specially when you are going through long text files. Note that though the ^M has two characters, Vim treats them as a single visible control character.
You can delete the ^M’s by moving the cursor over the caret and pressing ‘x’ in the command mode. Alternately, you can use Vim’s substitute command (used for search and replace) to remove all the ^M (CTRL-M) characters in one fell swoop.
To do the substitute action, in command mode, press “:” (colon, without the quotes) to start entering text on the mode-line at the bottom of the window.
Then, enter “1,$s/^M//g” (without the double-quotes) on the mode-line and press Enter. Presto, all your ^M’s are gone.
Do not enter the ^M in the above as a ‘^’ (caret) followed by an ‘M’. Instead, when it is time to enter this character, first press CTRL-Q to enter a mode where control characters can be keyed in and then press CTRL-M. This will actually insert the ^M (CTRL-M) as a special control character with the caret and the M (and which is treated like a single character though visibly it’s two characters).
To summarize, in command mode, type in the following