A couple of months ago I asked a question in this blog about a problem I was having with file transfers to Vista - it was giving me an error message that said only, "You must have permission to perform this action." Nobody came up with the answer. Maybe nobody is having the same problem? I hope not, because it turned out to be pilot error. Dummy me. Here's what was happening.Whenever I tried to copy a file across my home network from another PC to a machine running Vista Ultimate I got this weird error, "You must have permission to perform this action." It wasn't working. It just wouldn't let me do what I wanted.

Naturally, I blamed Windows Vista. I was already mad at Vista over User Account Control. Previous Microsoft operating systems allowed you to run them. Vista runs you. That is the lesson of User Account Control. The UAC pop-ups tell me what I already know I'm doing , then prompt me to click "Continue" for Vista's permission. (Actually, there's a solution to this - see Don't Shut Off Vista UAC, There's A Better Way.)

What made me even crazier about this file-transfer problem was that I could sit at the keyboard of the machine where the files resided and copy them to the Vista machine without any problems at all. And I could copy files from the Vista machine to the other machine from either machine.

Vista wasn't giving out any helpful information, either. You can type Vista error messages into the Vista help search box, but Vista does not admit to ever having seen them before. This is one of the major failings of Vista's help - and of most other help files, as well.

I finally decided to shamelessly abuse my status as a member of the press. I called Microsoft's PR agency and said I was writing about file-transfer problems in Vista and needed to talk to tech support. They bought it, and in due course I got a call from a tech-support guy who listened to my story and walked me through installing a remote-access utility on my machine.

He poked around on the Vista PC and spent so much time resetting file and drive properties that I was very glad I wasn't paying for the call by the minute. Nothing worked until he had me sit down at the other PC. Because he could see only the Vista machine, I held a phone to my ear while he talked me through things and asked questions. We were going through the Sharing settings when he finally asked the key question: "What are the permissions for the guest account?"

"Uh, guest account?"

"It's the one named Everyone on the user list," he said. Oops. There wasn't any guest account. How did that happen?I created an Everyone account. The tech-support guy restrained me from giving it full read/write access to the whole hard drive. We set it for just Read permission. He tried to copy the target files to the Vista machine. It worked. Problem solved. Elapsed time: 2 1/2 hours.

I learned several lessons from this:

First, I learned that it wasn't a simple problem. I felt like a dummy because of the "Everyone" thing, but hey, I'm not a networking professional, and it took a real professional, the tech-support guy, 2 1/2 hours. So make a note of this: when you see the "You must have permission to perform this action" - at least in a situation where more than one PC is involved - the problem may not be in the PC you're getting the error message on. Another lesson is not to confuse permissions like the guest account settings with security, like User Access Control.

Second, I learned that my home network is a dysfunctional mess. This doesn't surprise me. I've changed just about everything about it in the last few months, adding new machines, installing new OSes in old machines. And I've never been good at solving network problems. Now that I think about it, that PC that lacked a guest account has given me fits since it was running Win2K and I was first trying to set up a wireless network.

Third, the tech-support guy was right, I should practice better PC hygiene. Shortcuts like sharing the C: drive are an invitations to trouble. I need to redo my file-and-folder structures on all my networked machines. And I need to recheck the user accounts in each machine's Sharing settings, and maybe create some new ones specific to the user accounts on my various PCs so that I don't rely so completely on guest access.

So I got an answer to a nagging problem, but now I've got some nagging solutions - more work to do clean up the conditions that surfaced the problem in the first place. Sigh.