Recently I’m more involved with Windows 2008 Server and nuances Microsoft delivered with this release (ok, they started with Vista, but this is an OS I simply don’t care about). One such odd decision that MS team made was to replace “Run As…” in Explorer shell with Run As Administrator, removing the option to enter alternative account.
You can still use command line tool runas in the same way you can on XP/2003, which is fine if you want to create permanent shortcut on your desktop to launch some application as some other user (not necessarily Administrator).
It’s silly that they removed “Run As…” from the Explorer Shell as this was really a convenient way for me — all I needed to do is to right click target application, select Run As, enter proper (“ordinary”, “application”…) user credentials and I was done. I was not surprised when I found plenty of complaints on the net about missing RunAs in the shell, so it didn’t come as a surprise when I found that Mark Russinovich delivered an applet that corrects that mistake. Simply download and install ShellRunas and you’re back in business.