well if the old HDD is Not Working your Going to have a problem As if the Chip is not working Even if you load in a Dash on the New HDD it will Not Boot as it has to Be locked to work
Hotswaping Is more or Less easy
this is How i do it
Trun On xbox wait till you See MS Text After Fluber Boot Soon As you See the Text Unplug HDD's IDE Cable
Remeber Keep the Power Pluged In at ALL times Never shut the Power Off with IDE Unpluged
-Turn On PC with your Windows HDD on Secondery Master IDE BUT Befor it Starts Push the Pause/Break Button On your Keabaord
Ok Now Connect the Xbox HDD to Pc's Primary Master IDE and you'll have a PC hdd with Windows On Secondary Master IDE
-----|----|[xbox] <---Primary Master
-----|----|[PC HDD] <----Secondery Master
Ok Now you have evething connected Hit Enter On the PC's KeyBaord (you May need to hit it more then Once)
If all Goes Well it should Boot to Windows
Now just RUN xplorer360beta4 witch you can get Here
www.smdepot.net/zzk/xplorer360beta4.rarit should Load With a Error This IS OK after you push OK you should See 5 Partions
Partion 3 is C partion 4 is E