Tools > Options > IM & SMS > IM settings You should be able to remove the Conversation History either by changing "Keep History for XY" to "no history" or by pressing the "clear history" - button
Before I say anything, I should say I'm on a Mac. :/ But what I do is: -Go onto your history -Click on the conversation you want to delete -Then press "delete" on your keyboard -A box will pop up,...
For Internet Explorer 8, Firefox, and Chrome, press Ctrl + Shift + Del on your keyboard. This will prompt you for deletion of all your cookies, browsing history, form inputs, etc. Other browsers...