Do you have to use TightVNC?
Are you willing to try other software?
Is the computer that you are controlling on the same local network or are you doing this across the internet?
Have you ever tried UltraVNC? It might work - it might fail - it seems picky about video drivers or something... but it handles UAC pretty well. Sometimes you only see half of the popup dialog box. Click on Show details to see the rest of it.
Ahah! You suggested the same thing I used in the past before I started SSH sprees.
I've had good success with UltraVNC, minus the UAC issues of only seeing half the box.
Ultra VNC - Windows 8 Compatible
Also, are you using the latest installation of both VNC Applications? I know when I first started using it I had an old version installed and had major issues.
If the ideas above don't work, or UsernameIssues doesn't work, give this a try.
1. Remove VNC Completely - Service and all.
2. Reboot your computer.
3. Disable UAC Completely (I find it to be a major nuisance)
4. Restart your computer again.
5. Download/Install the latest version of UltraVNC (see if this works, then you can try your VNC)
6. Reboot for a third time.
7. Try to login and go on with it.
When I work on computers, I always disable the UAC. It's a major nuisance when you download, install, encrypt or decrypt something. It's even more annoying when you're coding a program, and it freaks out every time you're compiling software that has to connect to an outside source.
That's just my take on it.
