I don't ever recommend disabling UAC. You can setup an Administrator account for doing stuff like that somehow (did it once -- wasn't simple) but I've only ever need to resort to that to do stuff that was more or less illegal / way outside the realm of stuff you're supposed to be doing
You should learn permissions for dealing with files. Permissions are there to keep bad software from breaking / accessing stuff. As the owner of your PC with a super user account you can get around any permissions that exist. I don't recommend using that batch file anyway. Like the first time I installed Som C: was not even a valid drive. It should just have a .reg file in there, or the batch file maybe should just ask you where you copied the files so it can set the InstDir key without requiring editing.
Once you get things working you will want to setup XP Mode and a network share wherever you installed Som. Then you will want to map that share to your XP Mode Virtual PC. Then manually add the registry keys. Then find an XP disc, or find an image online / burn it. Then install the East Asian component. If that doesn't install Gothic / Mincho you'll need copies of those. You need to hunt down copies of those anyway for when you want to release your game. I dunno if you can just drag them out of an XP Font Folder or not. I know you can't do that on Vista/7. There may be other steps as well... I seem to remember more anyway.
But after you have all that setup, you will want to edit with XP Mode, then run the debugger from outside XP Mode. You can do that with the map editor, but be careful not to do anything with the two editors open. I find it more convenient to setup a shortcut for launching som_db.exe. It never gets locked that way and you don't need the map editor, which can be really slow on 7.
PS: If you're confident about the installer, then I'm guessing Tom's DoM project repository must be the reason I've so many odd assets in mine. Work on Som seems so fast day to day, but overall it seems so slow. Sometimes I add a cool new feature everyday. But it seems like I'm almost spinning my wheels with no end in sight. If you've ever seen Brother Sun, Sister Moon... Som seems to be my San Damiano for the time being. At the same time it's been a while since I've had the reward of working on stuff that actually has tangible improvements from day to day. When I was younger that would keep me going day in day out. But I suppose when you're young you feel like you've always got something to prove to someone