Remove ^M from text file

You can use sed:

 sed 's/^M// filename > newfilename

If you wish to use awk then do:

awk '{sub(/^M/,"")}1' filename > newfilename

To enter ^M, type CTRL-V, then CTRL-M. That is, hold down the CTRL key then press V and M in succession.

Update

As suggested by @glenn jackman in comments, it is easy to use \r then to get ^M

col < input > output

Or:

vim "+set ff=unix" "+saveas output" "+q" input