Hello,

I am new to this forum so please bear with me.. I am trying to open some old Yahoo messenger archives that are in the form of DAT files.. Can anyone help me thanks in advance

Are they .dat files? These are usually comma delineated ascii text files and look like garbage if trying to open in a web browser.
.dat files are usually text files I believe, and can be opened with notepad or wordpad.
A lot of people using outlook and outlook express have experience this problem but I'm not sure if you're problems are from someone sending from those programs to your Yahoo email address or not.
You might try the following link and download a winmail.dat file -
Dat file reader software by Bruno Marotta and others
Good luck