.evt
a file viewer is when u open ur files
application log, security log, system log
.PTX is the extension for files created by E-Transcript. You can download the viewer of these files at http:/www.reallegal.com/softwareDownloadETranscriptViewer.aspIt is also used by Pentax cameras, but the most unusual and difficult to find is the one I gave.
An image file. It is a Microsoft bitmap file. You can open it in almost any image editor or viewer
TBN files are a type of a JPG file extension. Therefore, in order to open TBN image files on Windows XP, you can use any standard image editor or viewer.
An AutoCAD viewer is a program used for viewing and editing AutoCAD drawing files. Typically you can create JPG files from your drawings and print them using an AutoCAD viewer.
The purpose of the MPP Viewer is to view Microsoft Project files. You can download the MPP Viewer software online for free from the Sourceforge website.
You can view pdf files on it, as well as word and other files apparently.
sai
There is list of programs that support DO file extension http://www.howopen.org/en/extensions/web-files/do
.XLS files are standard Microsoft Excel spreadsheet files. .XLT extension is used for the Excel template files. - Neeraj Sharma
Picture files no matter name they have they will definitely have an extension like xx.jpg . bmp and may more. window automatically will search for these files extension if asked to do so.