I had a client who was experiencing an equals sign being typed every time he typed a colon.
This feature can help to solve this problem or allow you to make easy short cut keys if you are typing extensive spreadsheets.
Click the Office icon and at the bottom click Excel Options. When the window opens click proofing.
At the top of the window click the Auto Correct button. Another window will come up.
In the Auto Correct tab in the Replace with section scroll down and find the : select it and click the delete button then press OK to close all of the windows
You can also add auto Corrections by typing the text you would like to replace in the Replace text box and the text you would like to replace it with in the With text box.
Please visit some of my other links below to help you with other computer questions.