I had to re-install Win XP this week because I put in a new hard drive.
Everything went fairly smoothly but now I find that I can't watch DVD's using
WMP. It says:

"Windows Media Player cannot play DVD video. You might need to adjust your
Windows display settings. Open display settings in Control Panel, and then
try lowering your screen resolution and color quality settings."

Tried changing resolution and color but that didn't help.

I tried the help button and the MS website says that I need a decoder.

I never knowingly installed a decoder before. Is something messed up or did
I install a decoder before with another program without realizing it?

Thanks.