How to block computers on same network

I have a new computer from HP that has Windows Vista Home Premium 64 bit installed. Mostly, it seems pretty good. It has been quite stable since initial trouble got ironed out (blue-screened severely, fresh out of the box from day one).

Here's my current problem...

My daughter came to visit over the holidays and brought her laptop with her. When she connected to my wireless network connection, her Windows Media Player popped up a message saying it found [computer name] and did she want to have access to media on that computer. She answered "yes" and proceeded to show me that she could see all my pictures and movies, and play my music.

Doing some experimenting, we opened Explorer and clicked on the Network line, and saw icons there for all the computers on this little home network. We opened one of the remote machines and discovered that we can read AND WRITE files to it, and can delete them as well.

This seems like a severe security hole to me - if I am mistaken, please explain.

How can I prevent these computers from being accessible to each other on the network?

Thanks in advance for any help you can offer.

 

You should disable sharing on whatever drives/folders you don't want shared over your network.

 

Thank you for your response. Sharing was the first thing I checked, but maybe I am missing something. When I right-click on any of the folders in question, select Properties, and the select the Sharing tab, I see it says the name of the folder and has the word "Shared" under it. But when I click on the "Share..." button, all I see in the form is "Owner". That dialog is titled "File Sharing", and the headline is "Choose people to share with"

I have chosen nobody.

The other button on the "Sharing" tab is "Advanced Sharing..."
The subsequent dialog shows the "Share this folder" checkbox NOT checked, and the remainder of the form is inactive (and all fields are empty).

Under the "Advanced Sharing..." button it says "Password Protection", and "People must have a user account and password for this computer to access shared folders."

I see no place to disable file sharing, and it appears to NOT be enabled. However, it clearly IS enabled, because on all 4 computers we can read/write files to the other computers (not to all folders, however).

How do I fully disable file sharing in Vista and Windows 7?

Thanks again for your response. I appreciate your time.

 

In Vista:

Go to Control Panel and switch to Classic View.

Go to Network and Sharing Center.

Under Sharing and Discovery, locate File Sharing.

Expand by clicking on the arrow. Select the radio button next to "Turn off File Sharing".

Click Apply.

I don't run Windows 7, but it is probably a very similar process.

 

Thanks. I found it - didn't have to switch to Classic View though.... not sure why that would even be necessary. Anyway, I did find that the default for File Sharing was "ON". That seems pretty bogus to me, but I'm no expert.
Thanks for your response, I appreciate your time.