Here is what you should do:
on a laptop, press number lock shown as num lock
press and hold down alt
laptops generally have numbers written beside the letters (i.e. u,i,o,j,k,l,m)
while holding alt (dont let go off alt until you finish writing down the alt code)
type in special code which represents the character
Example: alt+mkm8 (0208) should give you 'Đ'
For other characters go to system tools in accesories and open up character map.