CODE
I dont actually know if the error is #7 because i just go to the microsoft support screen with no number displayed, i was told that was the number.
error code is important because it tells you what kind of problem is there.. you cant just assume the error code..theres some inconsistency in your posts .. so lets get things cleared up:
1. you shouldnt be able to boot your softmodded xbxo's hd in your modded xbox.. since the hd is locked with different eeprom. It would give you error 06. If you can boot the softmodded xbox's hd with chipped console then it means that the hd is unlocked. so you should lock the hd using softmodded xbox's eeprom.
2. can you boot any burned dvd ( like slayers disk) when you have the 8 gig hd plugged in to the softmodded xbox. if you can do that then it means your softmod is working just the dashboard is missing. You can copy the dashboard files to E:\dash\ to fix that.