Hi, this is Gary Rosenzweig. Do you ever get an e-mail from a windows user, it has a file attachment, and you've got no idea what to do with it? You can't seem to open it up with anything. Maybe it has extensions like .ppt, or .doc, or even .rar. Well, let's go take a look at some of those files and what you can do with them on a Mac, on this episode of MacMost Now. One type of file you might come across is a .ppt or .pps file. These are PowerPoint files. PowerPoint is some software from Microsoft that is used to make presentations. It comes with office, and anybody with windows can play these back because windows comes with some PowerPoint playback software. You can't build PowerPoint presentations with it but you can play it back. So, windows users are used to sending PowerPoint things back and forth to each other. Mac users, of course, can't play PowerPoint files unless you have some software. You can get software like Microsoft Office, which costs a lot of money and you can play back and make PowerPoint presentations. You can also use Keynote, which comes with iWork , and is a lot cheaper than Microsoft Office. There are some free solutions, however. You can use the free office packages NeoOffice and OpenOffice. Both can open up PowerPoint presentations. Another way to do it is you can actually go ahead and upload a .ppt to Google Docs, if you really wanted to and you don't want to add any extra software. Still a third way to do it is to get your friend who sent you the file to actually export some of the format. Most modern versions of PowerPoint can export as .pdf files. You can open a .pdf file, so have them make a .pdf file for you and send it to you. Probably the most common file you might get is a .doc file. These are Microsoft Word files. Now, Microsoft Word, of course, is a very popular word processing program. It still doesn't come with Windows, you have to get Office. But a lot of people like to send .doc files around. If you work in an office, chances are that they put Microsoft Word on your machine, so you think it is okay and everybody has one. News is better here for Mac users because TextEdit, the free little editing program that comes with every Mac, can actually view and edit Microsoft Word files. But sometimes some of the more advanced features may get lost. You can get Microsoft Office and edit the Word files using Microsoft Word on your Mac. You can also use those programs I mentioned before, NeoOffice and OpenOffice, and also use Google Docs. Another less common file type is .xls, or Excel spreadsheet file. Now, you can do the same thing here and use some of this office software, you can get Excel for Mac, or you can use Numbers, part of iWork, to open it up. Even Google Docs should open these up as well. You may also get a .exe file. Now, this stands for an executable, or as us Mac users like to call them, applications. There is really nothing you can do with it; you need Windows to run a Windows application. So, you probably just want to tell the person who sent it to you, 'Hey, I've got a Mac, what are you sending me?' Or, chances are if you get a .exe, it's not really a friend that is sending it to you, but a piece of spam and you're lucky to have a Mac and not be able to run it because it's probably going to give you a virus. But, if you do need to run an executable program, there are ways to do it on your Mac. One, of course, is to install Windows and use Boot Camp and you can run all the windows software you want, as long as you install Windows using Boot Camp. You can also use the software parallels, or VMware, to install Windows and run it virtually so you can run Windows software inside your Mac. Now here is a strange one. Sometimes you might get a .rar file. What a .rar file is, is a certain type of compression. It's popular among programmers and artists so you may not ever see one but, if you get one of these, you're going to need a way to decompress it and find out what's inside. One way is to use StuffIt Expander. However, there are some people that complain that certain types of .rar files won't be opened by StuffIt Expander. There is another thing called UnRarX, there is the URL, and you can use that to open up what is inside one of those. It's also good to know that StuffIt Expander is a really good utility for expanding just about anything so, if you get some other type of file or compression thing that you can't seem to open, you can go to stuffit-expander.com it takes you to the SmithMicro site. You can download the free StuffIt Expander that may help you out. Okay, here's something you may have experienced. You get an e-mail from somebody, and instead of the attachment they claim it had, it has something called winmail.dat. What is this? Well, what winmail.dat is, it's something from Microsoft Exchange Server. It's a wrapper that takes whatever attachment they thought they were giving you, wraps it up in something that you, as a Mac user, or more accurately as a non-exchange user, can't decipher. So the file is there, the data is there, but you can't get to it. It is very frustrating, because not only can't you get to it, but the person who sent it to you has no idea how it got to be a winmail.dat file. But there is hope. There's a program out there called TNEF's Enough. You see tnef is the file type that a winmail.dat is. This is a Mac program that will allow you to decompress the winmail.dat and get the file out of there. If you've got a question about something with your Mac or your iPod or your iPhone, or even your Apple TV, let me know. I'll be answering some questions on the show soon. You can e-mail me at questions (-at-) macmost.com. Until next time, this is Gary Rosenzweig at MacMost Now.