Windows ME with toshiba DVD player

I have not been able to get the system restore disk to work on installing drivers for my DVD player. Every thing works fine on my laptop, but whenever I try and play a dvd it comes up with the error, that i need a software or hardware DVD decoder. What is the diffrence between software and hardware? Do I need both? Where can I find a decoder to play DVDs on my system. I tried toshiba web site and no luck, and HP wont help since I bought the laptop used. It is a XE3 Omni book, with 850 P3.If anyone knows of sites to download this software.Please let me know.