.CTT File

File extension ctt is most likely best known for its use in Microsoft Windows Live Messenger up to version 4.6 and older for its contacts file format.

CTT is a proprietary file format used by Microsoft software. it contains save list of contacts and groups used by the MSN/Live Messenger instant messaging program in XML format. It is used for exporting and importing of whole contact groups.

A typical *.ctt file looks something like this:

<?xml version="1.0"?><messenger> <service name=".NET Messenger Service"> <contactlist> <contact>first_contact@some_domain.com</contact> <contact>second_contact@some_domain.com</contact> <contact>third_contact@some_domain.com</contact> ... <contact>last_contact@some_domain.com</contact> </contactlist> </service> </messenger>

Microsoft abandoned the use of CTT format in newer versions. Latest versions of MSN grab contacts directly from social networks / e-mail clients or work with CSV format instead. However, it may be still possible to import .ctt file to latest MSN.

Considering the program was replaced by Skype, this file type is more than obsolete now.

This ctt file type entry was marked as obsolete and no longer supported file format.

This type of file is no longer actively used and is most likely obsolete. This is typically the case for system files in old operating systems, file types from long discontinued software, or previous versions of certain file types (like documents, projects etc.) that were replaced in higher versions of their original programs.

Files with ctt suffix can be typically found as old contact files for Window Live Messenger instant messaging client.

How to open:

You can import .ctt files by selecting File → Import Contact from a Saved file in the application window.You can view and edit a .ctt in any text editor.

How to convert:

Because .ctt is a XML based format, there is a way to convert it to CSV format used by the later variants of MSN. Rename the CTT file extension to XML file extension Open Microsoft Excel (or any good Spreadsheet program) and open in it the file you have just renamed Delete the first column (that will leave you with just 1 column of data) Save the file in CSV format