The MASM situation is more difficult than described so far. It is part of VC++ 7.

  * Microsoft MASM (aka "ml")

  * Free Netwide Assembler NASM.

 MASM was at one point distributed with VC++. It is now distributed with some

 Microsoft DDKs, for example the Windows NT 4.0 DDK and the Windows 98 DDK. If

 you do not have either of these DDKs then you can just download the binaries

 for the Windows 98 DDK and extract and rename the two files XXXXXml.exe and

 XXXXXml.err, to ml.exe and ml.err and install somewhere on your PATH. Both

 DDKs can be downloaded from the Microsoft developers site www.msdn.com.

 MASM is distributed with most versions of VC++. For the versions where it is

 not included in VC++, it is also distributed with some Microsoft DDKs, for

 example the Windows NT 4.0 DDK and the Windows 98 DDK. If you do not have

 either of these DDKs then you can just download the binaries for the Windows

 98 DDK and extract and rename the two files XXXXXml.exe and XXXXXml.err, to

 ml.exe and ml.err and install somewhere on your PATH. Both DDKs can be

 downloaded from the Microsoft developers site www.msdn.com.

 NASM is freely available. Version 0.98 was used during testing: other versions

 may also work. It is available from many places, see for example: