There are a lot of Free Software available for Windows. Some people think that Free Software = Linux, but you can also use some of these application on Windows.
Popular applications like Gimp or Open Office are available for quite a long time, but there’s also other applications like Pidgin available. Pidgin will replace all your Instant Message Applications. I’m a Pidgin user (both Windows and Linux versions) for some time now and it works like a champ.
You can find here a list of available applications:
Free Software replacements for proprietary applications on the Microsoft Windows OS