Why some file transfers are blocked

Windows Messenger .NET

File transfers are blocked when they contain content that could be used to damage your computer. When someone tries to send a file to you, Windows Messenger first checks to see if the sender is on your list of contacts. Next, the file is put through a security check.

Files that are blocked

Files are blocked when the following occurs:

The file is capable of carrying viruses or harmful code. For example, files with these extensions are considered unsafe for file transfer: .exe, .cmd, .wsh, .bat, .vb, .vbs, .pif, .scr, .scf. For a more comprehensive list of files that are generally considered unsafe for file transfer, see "Information About the Unsafe File List in Internet Explorer 6." (http://support.microsoft.com/default.aspx?scid=kb;en-us;291369)

Files that are allowed

You can receive the following file types from someone not on your contacts list:

Files with extensions .jpg, .txt, .bmp, and .gif (not a comprehensive list).

Files for which you need to make a decision

Certain file types should be opened with caution, even if you know the sender. If you receive a file of the following type from someone on your contacts list, a prompt will appear and you will be asked what you want to do with the file. You should only accept the file if you can save it to your computer's hard disk drive and, before you open it, scan it with an antivirus program.

These are the file types for which you will receive a prompt:

Microsoft Office System files: files with .doc, .ppt, or .xls in the file name.
Files from other applications, such as .zip, .wpd, and .pdf.

Note Note

If you are on a local area network with a firewall (in a corporation, for example), you might not be able to use Windows Messenger to send or receive files outside the firewall. Firewalls can be configured to block file transfers. Check with your network administrator.