Here are the steps that I followed to install MASM 6.15 on to my PC. Hopefully you can follow the same procedure and it will work for you too!
Step 1: Install the assembler software
From the CD included with the Irvine Assembly book, run the program SETUP.EXE. An installation program will start. Follow the prompts to install the assembler. I highly recommend you install into C:\MASM615 which is the default directory. If you choose a different directory, some of the batch files will not work because they assume that you have chosen the hard-coded path of C:\MASM615.
This step essentially places a number of files into a directory C:\MASM615.
Optional: An optional but recommended step is to modify your PATH variable to include c:\masm615. This will allow you to assemble from DOS if you so desire from any location. Modifying your PATH varies depending on what operating system you are using. If you are going to only use TextPad then you can skip this step.
Step 2: Install TextPad
Enter the TextPad directory on the CD and double-click TextPad4.exe which will launch the installer for TextPad. Feel free to put this program anywhere you like on the disk.
Step 3: Install a Debugger
If you have already installed Microsoft Visual Studio 6.0 on your machine then you can skip this step, as you can use the Visual Studio debugger.
Otherwise, if you are running Windows 2000 or Windows XP and do not have Microsoft Visual Studio 6.0 installed, then you can download and use Microsoft's free debugger WinDbg. A link to download this program is at http://www.nuvisionmiami.com/books/asm/debug/debugging.htm . Download and install WinDbg.
Finally, if you are running a version of Windows prior to 2000 or XP and do not have Visual Studio 6.0 installed, then you will be unable to debug 32 bit programs but will be able to debug 16 bit programs. You can either not use the debugger at all (which is possible but makes writing programs much more difficult) or if you need to debug 32 bit programs then I recommend you either upgrade to Windows XP or use the machines in the CS lab instead.
Step 4: Modify TextPad to add Compilation Option to Tools Menu
Next you must edit TextPad's menus so that you can build, debug, and execute your programs directly from TextPad. To do this, follow the directions at http://www.nuvisionmiami.com/books/asm/ide/index.htm . There are different paths to take depending on whether or not you are using WinDbg or Visual Studio for a debugger.
Do not follow the instructions for modifying TextPad in the HTML file on the CD, they are not correct!
If you are using Windows 2000 or XP and have installed your programs into the default directories, you can right-click and download the following REG file : TextPad_MASM.reg. It will automatically edit your registry to add the menu options to TextPad assuming you installed programs into their default directories. You can also edit the file to reflect the actual pathnames of your programs. It has the default paths for both WinDbg and Visual Studio so if you only have one of these installed, only the installed option will work.
Step 5: Test Your Configuration
Open the example program, AddSub.asm, located in C:\MASM615\Examples\Ch03\. If your configuration worked, you should be able to build, run, and debug this using the 32 bit tools. To test the 16 bit tools, try the example program AddSubR.asm located in the same directory.
Step 6: Whew, congratulate yourself by taking a break or eating something lush, rich, and decadent - you have successfully installed MASM!