I have two Vista Ultimate 32-bit OSs installed on my PCs here (one desktop for about 3 years, the other a laptop for 1 year), and have been experiencing the following rather irritating problem for a while on both of the computers:
Right-clicking on any shortcut in Windows, be it in Windows Explorer, the desktop, or the Start Menu, and then selecting Run as Administrator has absolutely no effect. I am of course running on an administrator account, and the expected behaviour should be for a UAC prompt to appear to confirm the execution of the given program.
This is persistent behaviour which I have not since been able to eliminate, even temporarily, on either of the installations. It is worth nothing that the issue appeared only a number of months after setting up the OS, and is quite possibly due to a program I installed at some point on both machines, which has corrupted something (perhaps a registry entry) that prevents the Run as Administrator action. Unfortunately, since I've virtually mirrored the OS configuration and programs installed on both PCs, there is no real possibility I can determine which setup program caused the issue by cross-comparison.
I have described exactly the same problem here on the MSDN forums, which some feedback, but nothing close to a solution unfortunately. The only real recommendation I received in the end was to wipe and reinstall, which is not a feasible solution for me.
Any suggestions here, even long-shots, would be most appreciated here, as I am getting fairly desperate for a resolution.