HELP!!!

When i start the ds with r4 in it it said couldn't find _ds_menu.dat. Is anybody able to help me?Thanks!

Well.. did you put _Ds_menu.dat on the sd card ?
There are 2 files called DS_Menu mine are a video file and a .dat file. you need to put both of them in there.

Sounds like a bad firmware install, follow the guide in the tutorial section and do a reinstall.

Is that the software that I can dl from the R4 website and that's call Kernel?

Yep, that's it.