best solution , is to get another source of that image of bt4 , and it would be much better of u download it from bt4 it self
BackTrack Linux Downloads | BackTrack Linux - Penetration Testing...

hope this help ...

http://www.hpl.hp.com/personal/Jean_Tourrilhes/Linux/Tools.html

How to get USB devices working under Linux


Linux Forums

good luck

nooooo its ok dont worry i used to unplug my hardware when i was try to install backtrack but dont worry its great system u gonna like beside follow instructions ovr here and u will be ok
...

HELLO ALLLLLLL , this forum is wat i been looking for thx alot , and it hink it s afresh start away from microsoft :)

thxxxxxxx man , was really helpfull