I want to get rid of Real Player

At least as my default player, I’d prefer Windows standard player.

Any ideas?

Open up Windows Media Player, go to Tools --> Options, then click on the ‘File Types’ tab, then tick the boxes of the formats you want Windows Media Player to be default on.

You can manually change the file associations as Tuco described, but RealPlayer may try to grab them back. You can disable this feature in its Preferences. You may have to poke around a little to find it; in version 8 it’s the Auto Restore Settings button under Edit|Preferences|Upgrade.