Replacing ^M character at end of line using VI editor ( ^H, ^G and so on..)

Some time these characters are placed when you convert file from DOS format to Linux format. These characters can be viewed only with Vi editor or either typing "cat -v" command for that file in command prompt. These characters are called control characters.

These characters can be deleted using ":%s/.$//g" command from VI prompt.
To replace character use it like ":%s/.$/replace/g" Press Ctrl Q+M, and this will character will come up. In some other format it can be typed using ctrl V+M.

But before doing all this do ":set ff=dos", to change file format to DOS.

At last a simple trick for Gvim on Windows XP:
:%s/\r/\r/g
This replaces unix carriage return by windows CRLF.

following is the list of Ctrl characters:

Hex Name
0x00 NUL
0x01 SOH, Control-A
0x02 STX, Control-B
0x03 ETX, Control-C
0x04 EOT, Control-D
0x05 ENQ, Control-E
0x06 ACK, Control-F
0x07 BEL, Control-G
0x08 BS, backspace, Control-H
0x09 HT, tab, Control-I
0x0a LF, line feed, newline, Control-J
0x0b VT, Control-K
0x0c FF, form feed, NP, Control-L
0x0d CR, carriage return, Control-M
0x0e SO, Control-N
0x0f SI, Control-O
0x10 DLE, Control-P
0x11 DC1, XON, Control-Q
0x12 DC2, Control-R
0x13 DC3, XOFF, Control-S
0x14 DC4, Control-T
0x15 NAK, Control-U
0x16 SYN, Control-V
0x17 ETB, Control-W
0x18 CAN, Control-X
0x19 EM, Control-Y
0x1a SUB, Control-Z