I am trying to install pywin32 for Python 2.6.
I have python installed but it's not in the regular c: drive but on the d: drive . The pywin32 installer does not find it and I cannot give the custom path to it.
I checked, thepython folder is the path. Is there a workaround this issue ?
I ran into this exact problem, but it seemed to me that my situation was a bit different and besides, I didn't want to have to use a registry hack.  So I started to post a new question.  Here's what I was going to write:

I have both 64-bit and 32-bit versions of Python 3.7 installed on my Windows 7 machine.  The 64-bit version is installed in C:\Python37 and the 32-bit version is installed in C:\Python37-32.  I have the pywin32 package installed in the 64-bit version but not in the 32-bit version.  When I start a command window, switch to C:\Python3y-32, and run "pip install pywin32", I am told that it is already installed in C:\Python37.  Yes, I know that.  I want it installed somewhere else.  I tried downloading a wheel file and installing that, with the same result.  I tried renaming my C:\Python37 folder to "C:\Python37 64 bits" and renaming C:\Python37-32 to C:\Python37, but the pip gave me a fatal error:
Fatal error in launcher: Unable to create process using 
'"c:\python37-32\python.exe"
"C:\Python37\Scripts\pip.exe" install "c:\users\\downloads\
pywin32-223-cp37-cp37m-win32.whl"'
(line breaks added for readability)

But then I looked again at that error message and realized that the quoted string is a command.  I copied that string, switched to the C:\Python37-32 folder in my command window, pasted the string, removed the reference to C:\Python37, and ran it.  No problem.
Problem installing pywin32