You don't uninstall programs by simply deleting the folders or files or whatever. You need to go to add/remove programs and select the proper name and click on uninstall or remove!!!!
In case of MSN Messenger, go to add/remove programs and click on "MSN Messenger" and choose "remove"...
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And again you're double posting (even triple posting), THIS IS NOT ALLOWED!!! If you want to add something to your previously post then use the button... Stop making multiple posts in a row!