Missing filename extensions

The other day i had to re-install everything on my laptop as the op. system got corrupted (im on XP)

now ive noticed that none of my files ie mp3's , pictures etc have filename extensions

i.e. a word document is just called 'Document1' instead of 'Document1.doc'

how can i make it show extensions? i want extensions!!

thanks

open Windows Explorer
Select Tools>Folder Options>
Then click the View tab

Uncheck the option that says "Hide extensions for known file types"
Click Ok and you'll be back to "normal"

thanks a lot!