UPDATE: May 4th, 2009
I posted a link to the MASM Forum to see if there are better ways of doing this and if those ways can help more people than mine. MASM Forum users suggested different methods (all untested by me but probably by them):
- Installing to a fixed partition and then copying it to a networked partition (wouldn't work for me as fixed partitions are not writable at the moment)-Hutch
- "You can extract SFX exes just as easily as archives, navigate in the 7zFM to install.exe and press Extract, or right click on install.exe if you have shell context menu integration for 7z and press "Extract to". You can also extract with Total Commander if you have it by pressing Alt+F9 on the install.exe."-drizz ; now that you have extracted the files you should run makelibs.bat "Also seems to work on SUBST drives. I use that to create drives for M: for Masm stuff and V: for visual foxpro stuff, and i create a batch file and save it in the startup folder: (see the rest of the post for the actual 2-line script)"-fearless
Motivation
I wanted to go from being x86 assembly literate to decent. So, I installed MASM...because it's nice--but not nice enough to install on my network drive. So, I modified MASM to install on network drives.
In Pictures
In words
Let me say that OllyDbg, by Oleh Yuschuk, is my favorite debugger and I always turn to it first when I need to "debug" executables or "inspect" DLLs.
I opened up OllyDbg and debugged the MASM install.exe file. I started looking for Win32 API calls to get the list of drives and found them very quickly.I spied a suspicous comparison of the return value of GetDriveTypeA to the 3. Looking at the GetDriveTypeA documentation from the MSDN I found that a return value of 3 is typically associated with a hard disk while value 4 is specifically associated with a network drive. Clearly, this is the point where MASM filters out all non-fixed storage media.
Basically, I wanted the jump to be taken either all the time or when my network storage drive caused GetDriveType to return 4. In a display of my x86 inabilities, I did not think first to just to erase the JNE, but to change the 3 to a 4. It worked. If you are doing this yourself, just fill the jne with NOPs. Both approaches are described in the story.
I would give everybody the modified install.exe binary but I think it's illegal and if you really want MASM to install on a network drive you just have to change one instruction. I may provide a "trainer" later on to do this automatically.