As above pointed out, need the file extention.
The 3 letter extention identifies the program to open the file.
After coping the file, does the size match the original file size. or right click it and click on properties.
You say a dos file. In it trues form that means that it was created under dos, either by a 3rd party program or from a dos command line.
Windows 7 should open any Dos file with an extention of .txt
The .bas file that kenrivers indicated would have been created by Dos Basic and would not be read by windows 7 unless it was generated as a text file. You couyld right click it and open it in word pad - but pointles as that would be a source file for a program writen in basic.
A .exe, .com or would be a file that executes and in most cases if created in Dos will NOT run under windows 7 64 bit as it would undoughtably contain 16 bit code. A .bat is also simular to a program and would be meaningless under windows.
Normally windows will display a error message indicating that it does not know what program to use to open the file.
If the File is really a progrm (ie .exe) and the recipes are opened when the program opens. Try running a dos window and go to where you placed the file and type the name. May work with windows 7 32 bit, but probably would need to down load "DosBox" to get it to execute under windows 7 64 Bit.
http://www.dosbox.com/download.php?main=1