1- NASM
Download NASM ( Click on this link ) and install it.Now open the cmd and change your directory to the installation folder using these instructions
> C: > cd C:/tutorial/NASM
First instruction is for changing the drive to C if you are in any other drive.
Second instruction is to change current directory to our installation directory. In my case I have installed nasm in "tutorial" folder of C drive.Now you will have to put all your ASM files in this folder to assemble/compile them .
Alternatively, you can just go to the installation directory through WINDOWS EXPLORER and click/run "nasmpath.bat" file . This will setup path ( skipping everything we discussed above ) and open a new console/cmd/command prompt for you.
Now you can run nasm from anywhere in the cmd. but you will have to be in the directory where your code files are placed.