Windows Live Messenger 8.5.1302
With MSN Messenger you can chat online instantly in real time with friends, family and colleagues. It's faster than e-mail, more discreet than a phone call.Chat using a webcam, send text messages to mobile phones, and express yourself instantly online in real time with new, cool emoticons.MSN Messenger looks like you! Sign in with your own picture, create your own emoticons, and represent yourself with new, cool backgrounds!

Miranda IM v0.7.7
Miranda IM is a multi-protocol instant messaging client for Windows. Very light on system resources and extremely fast, Miranda IM requires no installation and can be made to fit on a single floppy disk or USB drive. Featuring a powerful plugin-based framework and boasting over 350 plugins, Miranda IM is one of the most flexible and customisable messaging clients on the planet.

Windows Live Messenger
Windows Live Messenger is the next generation of MSN Messenger. It supports video chats, phone-to-phone, phone-to-PC calls and conventional text chats with full support for emoticons, font formatting and more. Windows Live Messenger integrates support for Yahoo!, enabling you to chat with your Yahoo! buddies from the same application. Other features include file sharing, SMS messaging, Live Contacts address book and more. This version offers many improvements over the old MSN Messenger, and the video chat produces high quality, full motion video, even in full-screen.

Google Talk
Google Talk is text and voice instant messenger, that enables you to communicate with your friends via voice (microphone required) or traditional text messages. It offers the standard features, including user blocking, online status, and contacts display as well as file transfers and voicemail. Google Talk integrates with Gmail and allows you to import all your contacts.

Pidgin Portable
Are you tired of heavy instant messengers, which are slow to load, full of colours, animations, and add-ons that put a considerable strain on the whole performance of your PC? If so, then consider an alternative, lightweight solution like Pidgin Portable which has the advantage, like its name says, of running from a USB pen drive. You will be able to use it wherever you are, without having to install anything on any computer while travelling or working.Just plug in your USB pen drive and run the exe file to have all your contacts from different accounts, available for a chat. Pidgin Portable is able to connect to multiple networks: AIM, MSN, Yahoo!, XMPP, ICQ, IRC, SILC, SIP/SIMPLE, Novell GroupWise, Lotus Sametime, Bonjour, Zephyr, MySpaceIM, Gadu-Gadu, and QQ. You will never again need to use different messengers for every account you have, Pidgin manages them all at once. Although the interface is rather simple and the icons available are limited, the program is light and lets you choose a picture to represent you.

Trillian
Trillian is an instant messenger which combines IRC, ICQ, AIM, YAHOO, and MSN Messangers all into one easy to use utility.