You must keep your files always. Securing your files will save your precious time.
Let me remind you on the following tips:
a. Save your document from time to time by pressing CTRL+S. You may never know when your PC crashes or the power will be down.
b. Do not save your work in a drive where your Operating System is located.
c. Try to create a copy of your files by saving it with a new file or by copying it into an external drive or a portable storage.
d. Print your document.
Hope this helps you in keeping your documents.