i went to yahoo chat,and got a lot of ims.now all these peoples names are in my messenger address drop down bo?

Deleting your Yahoo Messenger cache will clear all those names on the drop down contact list on Yahoo Messenger. First exit Yahoo Messenger by right clicking the Yahoo icon by your clock and choosing exit.

Now, right click the Yahoo Messenger icon on your desktop and choose Properties. On the Shortcut tab of Yahoo Messenger Properties click the button near the bottom that says Find Target. This will open the Yahoo!/Messenger folder in Program files. Scroll up until you see the Cache Folder and open it. You can delete everything in this folder. When you relaunch Yahoo Messenger you should find the names gone.

Please note that the above instructions are for XP. It might be the same in Windows Vista but not sure.

First right click on their icon, scroll down to stealth settings and change them so that you appear permanently offline. Then click on messenger, top left on the messenger window , scroll down to preferences, click and scroll down to ignore list, click and in the next window add them to your ignore list and click o.k. Then go back right click on their icon and delete them. This way they are history

right click the person you want to delete and click delete so it will delete the person you dont want to be in your contacts and addres book