If you use Skype for chatting with multiple contacts over time, you might find your chat history takes up too much memory. Or, there may be occasions when you want to edit or remove a message you've sent in error, or clear a contact's chat history without deleting all Skype messages from your history.
Deleting all chat history
If your Skype settings are set to record chat history forever, you might want to change that to free up a little memory. From Skype, click on Tools from the top menu bar, and then Options from the drop-down menu. Select Privacy from the left column, and if necessary click on Show Advanced Options to view more options.
To set how long Skype should keep messages and files, click on the drop-down menu beneath Keep History For, and select an option. To clear the current contents of the chat history, click on the Clear History button. However, be aware that this will remove all contents of the history, including SMS and instant messages, call logs and voicemail, and even file transfers, so if there is anything you want to save, you should do that first.
Editing or removing a recent message
If you've sent a message in error (or anger) and want to remove or edit it, provided you act fast and do this within one hour of the original message, Skype allows you to do that. All you have to do is right click on the message, and if it is within the one-hour timeframe, you will find two additional menu items, Edit Message and Remove Message. Clicking on Edit message returns the message to your chat window, where you can alter the content before hitting enter to resend. Clicking on remove message will delete the message contents, but an entry remains in the timeline that a message was sent and deleted.
Partially removing older chat history
Skype itself doesn't allow partial removal of chat history, so if you want to do this, you'll have to install additional software. SkypeX allows you to select individual messages or an entire contact's chat history and delete it. Kudos Chat Search for Skype also allows you to search your Skype history using keywords and filter the results by age of message or recipient. You can then select the messages you want by clicking on checkboxes alongside them, and either export to a file or delete the messages.
However, using external tools to find and delete message you no longer want to see will only remove them from your chat history, it won't remove them from the recipient's computer. The only way to change the message the recipient views is using the edit or remove options within one hour of sending the original message. So, you should remember when using Skype that just because you have your chat history set to "No History," or you choose to delete messages, does not mean that they may not be recorded on another computer, and choose your words wisely.