How to delete a games i backed up on my hard drive (psychonauts)? i own the game and it was a test subject for using dvd2xbox. but now how do i get rid of it?

Use the file manager in your dash, XBMC, or in dvd2xbox, then delete from there. Or you can do it with boxplorer.
OR...you can FTP and delete from there

but dosn't spread the files in different places when you are ripping them? like some in C:/ and some in E:/ and stuff?

try it.

Read the FAQs on website. HERE

don't do guess work.

Do what chorizo1 says.

If you told DVD2Xbox to rip a game to F:\Games\Battlefront.. it's not going to decide to save, say, the sound files to E:\UDATA\A4E645800\Youneverfindmehere\

Newer versions of DVD2XBOX have a game manager built-in, which allows you to select the game from a list of installed games and delete (including the gamesave if you want).