stop using Internet Explorer. use Firefox. Stop using Windows. Stop using Mac. Use Linux. Use Ubuntu.
I would like to ask what you do to receive that message. I would presume that "t.psd" is an Adobe Photoshop image and for that you need to have Photoshop. So I also need to ask you if you have Photoshop. If not, e-mail the file to someone that does and ask them to convert it to JPG or something. One would think that you receive the message when trying to open that file. If not, as a previous respondant said, do a virus scan. then tell us all the outcome!!
Yes, the question is what you were doing before the message appeared if you were trying to open the file and you don't have the right software for it then you should try installing it.
Yes, .psd is the default file extension for Photoshop files. All that message means is that you don't have Adobe Photoshop installed and I guess that some web site you visited had that file; t.psd, as an image on the page, (odd to do that) and when it tries to load the page it can't find anything to read that file. It isn't a virus.