Hi Cin dy,
Thank you for posting your query in Microsoft Community forums.
From the problem description, I see that you want to how to enable touch screen on Windows 8 computer.
I will surely help you to fix this issue. Let's try few steps which will help you to resolve the issue.
If the computer has the features for touch screen computer and you want enable it you may try the steps in the article and check.
a. Press Winkey + Q.
b. Type **Control Panel.**c. Go to **Hardware and Sound.**d. Click on **** Pen and touch.
e. Click the **touch tab.**f. Enab le use your finger as an input.
You may refer the link for additional information.
Touch: swipe, tap, and beyond
http://windows.microsoft.com/en-IN/windows-8/touch-swipe-tap-beyond
Hope this information helps you. If you need any further assistance or information about Windows, I will be glad to help you. We, at Microsoft strive towards excellence.