I couldn't get your installer to work for the life of me, when I opened it up it displayed the following popup:
One would only assume it can't find the right path, and for some reason doesn't let your choose your install directory. Opening it in a dissasembler I see that it's trying to grab the path from Computer\HKEY_LOCAL_MACHINE\SOFTWARE\paint.net\TARGETDIR, so I went there in regedit and low and behold for some reason its pointing to a D drive which is my blueray disk drive. I recommend you add a check that checks if the directory even exists because for some reason you don't, and if it doesn't prompt the user with a folder picker. I recompiled your installer that does all of this already and it works fine, here are the changes I made.
