User blog comment:V3-CHAN/MAYUs BROKEN!!!!!!/@comment-25352448-20150101215015/@comment-32500188-20150103062835

That's one of the possible problems. Definitely shouldn't be installing anything to your "Roaming" folder... if I'm not mistaken, that's an admin-locked folder in the first place, so that's why it's wasn't letting you install it. It should be setting the files to your C:\Program Files (x86)\VOCALOID3TINY directory instead. (This is where it also should install Tiny VOCALOID3 Editor as well.)

Second thing... this "download failed ERROR code:abunchanumbers" thing puzzles me... I'm thinking you mean this one:


 * VOCALOID 3 Installation failed!
 * Error code: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX(-X)
 * Click Finish to exit the wizard.

If that's the case, make sure you're either running under an account that is classified as an admin account, or right-clicking the setup.exe file and choosing "Run as administrator". Chances are it's not letting you install anything because the account you're logged into doesn't have sufficient privileges to allow certain changes on the computer.

And if that doesn't work, try installing it in compatibility mode for Windows 7. (Right-click on setup.exe file > Properties. Click the Compatibility tab. Check the "Run this program in compatibility mode for:" box, then go to the drop-down menu and select Windows 7. Click OK, then try running the installation to see if it works.)