Messenger Popup Blocker Free Edition
Messenger is a service that comes with Windows XP, NT, and 2000. Advertisers have taken advantage of this by sending ads over this service. Messenger Pop-up Blocker is a free program that blocks 'messenger pop-ups' from appearing on your desktop. It does not block other pop-up ads while surfing... Messenger Popup Blocker does not in any way disable you from instant messaging (AIM, MSN Messenger, ICQ).
http://www.capehostpro.com/downloads/messenger.exe - 261Kb - Download - Screenshot

Messenger Spam Block
In order for you to be able to easily stop messenger spam pop-ups from appearing on your computer, we developed a small free utility: Messenger Spam Filter. Windows, by default, leaves the messaging service active upon installation. Once deactivated, the messenger spam can no longer invade your... Messenger Spam Filter allows temporarily deactivating or permanently disabling the Messenger service, Messenger Spam Filter temporarily deactivates or permanently disables the Messenger service, protecting you from annoying Messenger pop-up windows.
http://www.spamliquidator.com/files/messenger-spam-block.exe - 248Kb - Download - Screenshot

Pop-Up Stopper Professional
The only privacy product to block pop-up windows and clean tracking files in every browser on every Internet connection. No matter how you surf, you are protected. Pop-Up Stopper Professional blocks, or quickly closes, pop-up and pop-under ads in ALL browsers, including FireFox, AOL, MSN,... This product even blocks those new, annoying Messenger Service Spam windows. ... Preserve bandwidth by stopping pop-up windows before they load! ... Play one of many fun sounds when a pop-up window is blocked.
http://www.popupstopper.net/downloads/PopUpStopperProfessional.exe - 1,000Kb - Download - Screenshot

IMterrupt Home Version
IMterrupt Home Edition controls and blocks access to Instant Messaging and peer to peer services that waste time and that can infect your home PCs with viruses or even allow your family to be endangered. Free trial version available - sets up in less than a minute. ... Blocks all popular services: MSN Messenger, Yahoo Messenger, ICQ, AIM, Skype, eMule, iTunes, and more. ... You can also block popular peer-to-peer file sharing programs, and individual web sites. ... IMterrupt Home Edition allows parents and guardians to effectively block and control the most widely used instant messaging...
http://www.imterrupt.com/download/IMLHomeSetup.exe - 3Mb - Download - Screenshot

IM Lock Home Edition Single User
IM Lock Home Edition controls and blocks access to Instant Messaging and peer to peer services that waste time and that can infect your home PCs with viruses or even allow your family to be endangered. Free trial version available - sets up in less than a minute. ... Blocks all popular services: MSN Messenger, Yahoo Messenger, ICQ, AIM, Skype, eMule, iTunes, and more. ... You can also block popular peer-to-peer file sharing programs, and individual web sites. ... IMLock Home Edition allows parents and guardians to effectively block and control the most widely used instant messaging programs.
http://www.comvigo.com/downloadIMLock/IMLHomeSetup.exe - 2Mb - Download - Screenshot

IMterrupt Professional
IMterrupt controls and blocks access to Instant Messaging and peer to peer services that waste time and compromise computer security. Free trial version available - sets up in less than a minute. Blocks all popular services: MSN Messenger, Yahoo Messenger, ICQ, AIM, Skype, eMule, iTunes, and more. ... A simple password that you set gives you the ability to block access to chat, web sites and file sharing all of the time, or according to a schedule of your choosing. ... You can also block popular peer-to-peer file sharing programs, and individual web sites.
http://www.imterrupt.com/download/IMLSetup.exe - 3Mb - Download - Screenshot

Pop-Up Stopper
Block Netscape, Internet Explorer, Mozilla and desktop pop-up windows with the latest upgrade of this small tool, now with added support for Mozilla, and new technology to block annoying Messenger Service and GAIN adserver desktop ads! No need to adjust proxy settings, or add sites to a list. ... Pop-Up Stopper is very small, and easy to use. ... Complete with full Install and Uninstall, and a complete setup wizard and online help file, and free unlimited tech support. ... The latest version includes automatic updates, new ad-blocking technology, easier user interface, more sound and...
http://www.popupstopper.net/downloads/PopUpStopper.exe - 414Kb - Download - Screenshot

IM Lock Enterprise
IM Lock controls and blocks access to Instant Messaging and peer to peer services that waste time and compromise computer security. Free trial version available - sets up in less than a minute. Blocks all popular services: MSN Messenger, Yahoo Messenger, ICQ, AIM, Skype, eMule, iTunes, and more. ... A simple password that you set gives you the ability to block access to chat, web sites and file sharing all of the time, or according to a schedule of your choosing. ... You can also block popular peer-to-peer file sharing programs, and individual web sites.
http://www.comvigo.com/downloadIMLock/IMLESetup.exe - 3Mb - Download - Screenshot

IM Lock Professional Single User
IM Lock controls and blocks access to Instant Messaging and peer to peer services that waste time and compromise computer security. Free trial version available - sets up in less than a minute. Blocks all popular services: MSN Messenger, Yahoo Messenger, ICQ, AIM, Skype, eMule, iTunes, and more. ... A simple password that you set gives you the ability to block access to chat, web sites and file sharing all of the time, or according to a schedule of your choosing. ... You can also block popular peer-to-peer file sharing programs, and individual web sites.
http://www.comvigo.com/downloadIMLock/IMLSetup.exe - 2Mb - Download - Screenshot

Message Killer
Have you ever had an advertisement pop-up out of nowhere on your desktop? This message was sent to your computer through a built in feature that Microsoft included in your copy of Windows 2000, NT, or XP. These types of spam messages are worse than unwanted e-mail since you dont even need to... Message Killer will block each and every pop-up ad sent through Microsoft's Messenger Service. ... With Message Killer, you can block these unwanted messages forever with the click of a button! ... No longer do you have sit and wait as your computer freezes or crashes due to one of these messages.
http://www.voytech.net/messagekiller.exe - 157Kb - Download - Screenshot