Unhiding OS files is probably not so simple a fix, but always willing to try simple first. Not sure how you missed it either, but you told joseibarra in Post #7 that his suggested folder options setting had already been done except for Operating System files. You seemed to think it unnecessary, and it may be, but you could try it for a time while troubleshooting, then change it back. My personal preference, born of years working in malware removal, is to keep these files unhidden, but that is not the right choice for everyone.
Yes, the page you linked to is one that I looked at but not all. I like to find two or three threads or pieces of relevant info when researching suggestions on things I haven't done myself--and when possible or at least partially convenient, I try to reproduce or follow instructions myself to see if they work--but haven't done that in this case because I can't think of a way to reproduce what your ultimate goal is.
EDIT: I couldn't Run as Administrator,because, as I said, the option doesn't show up in the right-click menu; not even when the .ini is opened from the desktop. And when I tried to overlay the edited file on the file icon in the pinemhi_1_5 folder, there was no Paste option in the right-click menu. (Growl)
First, I prefer that you not edit your post when giving feedback on what works/didn't work or if relaying important info. That's because I have my email notifications set to include the post contents when you reply. Thus I might begin researching what to do before actually coming back to the thread--sometimes making all the research in vain when new info is added. That wasn't the case here and it really isn't a big deal but just wanted you to know there is really no problem with making a new post when you have info of significance--moderators can tell that you aren't flood posting.
So you were able to save the modified .ini while it was on your desktop but now you can't get it back in the pinemhi_1_5 folder? Have you tried drag and drop? If that doesn't work, try moving the old .ini file out of the pinemhi_1_5 folder and see if the edited one will move.
The more involved thing I mentioned trying really isn't too complicated, just a bit more to it than what we've tried so far. That is the solution posted by the OP in the thread you just linked to. Try toggling UAC off and on. Go to Control Panel (set it to large icons instead of category), open Action Center, click Change User Account Control settings, then move the slider all the way to the bottom to Never. To re-enable, put it back to where it was. Reboot after each change. I would try it both ways.
If none of these suggestions help, we might try taking ownership of the program files folder, but i want to research that a bit more to know what are the consequences of such a change.
I suppose you have a good reason but I have to ask anyway--can you not just reinstall the program in question and point it to your F drive--or the standard program files on C: for that matter? That way you wouldn't have to modify the file path in the ini file.