I'm experiencing a very strange issue on a Windows 7 x64 machine. I'll try to explain the best I can, so it can't be short. Lots of thanks in advance for your patience.
So Win 7 x64. I'm working under an administrator rights account, and I have UAC enabled. What happens is that when a program needs elevation to do a task -and it knows how to ask for it, no ancient executables -, if it's running from -user- temp folder, it simply doesn't ask for it, and then fails.
I suppose it's not clear, so let's take a step-by-step look at what happens when I execute a program that needs elevation from any directory. If I try to launch, f.ex., TrueCrypt, I execute it, it automatically detects that it needs elevation, and it doesn't have it, so it asks for it (UAC prompt, click yes, the program runs normally).
Now let's take a look at a program that runs from temp. I'll choose an NSIS installer like Firefox one. I execute it, it automatically decompresses to temp, and then setup.exe is launched from temp. This setup.exe executable should ask for elevation, but it doesn't, just tries to run in the current context and then the process dies. It's like if, in the moment of checking elevation, decided it already has when this is not true.
But if I launch the NSIS installer directly with administrative rights, it decompresses to the same temp folder, then setup.exe inherits elevation and runs ok.
Another strange note I must add is that automated update services, like the Mozilla one, or for example the Google Chrome one, also fail to install the updates. And this is even stranger because these services run with administrative privileges and afaik they download the updates then launch the installers with administrative rights. But what happens is the same that in the first case, the service launches the setup.exe and automatically the process die.
The OS has been installed for a year and working ok until today; of course I don't mind to reinstall my workstation, but I'd love to understand what's happening here. The issue began to happen a normal day, I haven't installed nothing strange recently.