"An error occurred when writing to the file C:\Program Files (x86)\UTAU\utool.dll. Please make sure you can access this directory." (according to Google Translate)
I'm not familiar with this error, but it might help to try installing UTAU in Documents instead of Program Files.
Have you tried checking C:\Program Files (x86)\UTAU to see if the file utool.dll exists already? If it does, try deleting it and redoing the installation. Sorry if this doesn't work! ^^;