Hello Clo;
I read the answers to the other questions ... and it looks like they were all very straight forward -- the information is for the most part correct. Especially the info about WINE.
I wanted to add a couple to thoughts that might make help you to use you computer better.
1. Linux is not the same as MS Windows ... it is very different. In some ways Linux is far better than MS Windows. The key thing to remember is that the things you know about MS Windows might not apply to Linux.
For instance the need for a virus checker (or anti-virus) in Linux is negligible ... LInux is pretty much virus resistant it is made that way. Becuase there is no need for an anti-virus on Linux systems ... the computer runs more efficiently. This is one reason why people often claim the Linux machines are faster ... the machine isn't faster it is just doing fewer operations. It works better.
Another thing is de-fragmenting the hard drive ... the Linux file system doesn't fragment files in the first place, so a de-frag program is not needed.
2. Installing programs in linux is again very different than installing programs is MS Windows. Sometimes it is much more difficult (sometimes it is much easier too).
3. Peripherals, like printers, modems and webcams sometimes don't have Linux drivers and thus will not work. Getting the right peripheral is key.
I hope that helps you understand a little more about Linux ... I recommend you get a "beginner" Linux book.
Down with the Microsoft hegemony!
Bill