Sounds like people might be running into User Account Control (UAC) issues in Vista, which is a Windows security implementation that will pop up and ask for a WINDOWS administrator password if Windows thinks that the action might be "potentially harmful" -- (like, say, moving or renaming an icon on the desktop.)
It's meant to protect computers from neophytes and teens/children installing the latest 3,000 trojans and virii onto your computer, but it is way over-implemented.
From Windows help:
User Account Control (UAC) is a feature in Windows that can help prevent unauthorized changes to your computer. UAC does this by asking you for permission or an administrator‌ password before performing actions that could potentially affect your computer's operation or that change settings that affect other users. When you see a UAC message, read it carefully, and then make sure the name of the action or program that's about to start is one that you intended to start.
By verifying these actions before they start, UAC can help prevent malicious software (malware) and spyware from installing or making changes to your computer without permission.
When your permission or password is needed to complete a task, UAC will alert you with one of the following messages:
Windows needs your permission to continue
A Windows function or program that can affect other users of this computer needs your permission to start. Check the name of the action to ensure that it's a function or program you want to run.
A program needs your permission to continue
A program that's not part of Windows needs your permission to start. It has a valid digital signature indicating its name and its publisher, which helps to ensure that the program is what it claims to be. Make sure that this is a program that you intended to run.
An unidentified program wants access to your computer
An unidentified program is one that doesn't have a valid digital signature from its publisher to ensure that the program is what it claims to be. This doesn't necessarily indicate danger, as many older, legitimate programs lack signatures. However, you should use extra caution and only allow this program to run if you obtained it from a trusted source, such as the original CD or a publisher's website.
This program has been blocked
etc., etc.
