error 21 help

i seen tons of post for this but none really help...i have had this error once before but all i needed to do was put spilnter cell which is the one i soft modded my xbox with....well now its an error 21 and it wont ready ANY games....any help? am i gonna have to do a hotswap? ty in advance

 

Since the xbox won't load any original game and you can access to hdd, hotswap is the last option.

 

go here and read the guide and discussion.
http://forums.afterdawn.com/thread_view.cfm/1/320818