64-bit windows assembler
32-bit, 64-bit, assembly, compatibility
Solution
Yasm(*) is a modern, multi-platform NASM-rewritten assembler which is capable of assembling for both x86 and AMD64/x86-64 instruction sets.
However... What you probably mean is that you need a linker to link the assembled object code/file(s) to create an executable file. At least the completely free MinGW(Minimal GNU for Windows) project package ships with a linker(called ld) capable of assembling both 32- and 64-bit Windows executables from object files(ELF and PE object format, at least).
You can definitely cross-compile/build 32-bit projects in a 64-bit environment and vice versa, given that you supply correct command-line parameters to the assembler and the linker. Please refer to the documentation of the tools of your choise for more precise details.
*) http://yasm.tortall.net/
Problem
I want to program 64 bit windows assembly (preferably using NASM). I have looked quite a but on google but it seems that I cannot find a 64 bit windows compiler. Some site mentioned ml64 but it seems like it is no longer included in VC++. I have tried with 32 bit assembly, but obviously it just crashes on my 64 bit machine. Is it possible to write, compile and run 32 bit assembly applications on a 64 bit windows machine? Or should it be written and compiled for 64 bits? Thanks.