Easy Backsups:

= Pen Drive + MS Briefcase

Go to your Desktop
Right Click - New - Briefcase
Select all your important folders (e.g. My Documents) & then Edit - Copy
Right click the Briefcase & Edit-Paste
(this will set-up synchronised copies of your folders / files inside
Briefcase)
Drag the Briefcase to your pen drive (or zip drive)

Then at each day's end, attach your pen / zip drive and double-click its
Briefcase.
This will automatically update it , to include all that day's work done in
these folders

Easy & stress-free !