I've created a live usb of back track 5 r3 using unetbootin, when i tried to run it on my lenovo g50 70 laptop it shows an error like " kernel panic not syncing attempted to kill init ", but when i use same usb stick on hp pavilion 2000 it works perfectly, both are 64 bit architecture laptops and i created a 64 bit backtrack os. The difference between two laptops are lenovo using win 8.1 os & hp using win 7 os…
what should i do to run backtrack 5 rather than kali linux?
help me. 
The most likely reason is that the boot setup or ramdisc image (initrd) does not include the proper drivers for that machine; it's missing something essential for the OS to boot up properly.
Backtrack is an older distribution than Kali, the machine with the problem likely uses some hardware than was released after the last backtrack update.
It may be possible to update the boot files to include the needed drivers - but you need to know what the difference is between the machines.
Doing "lspci" on each from Kali will give you a device list - compare the two and see if you can see anything that stands out, such as an HDD interface.
If you can scroll back up the kernel panic screen to look what started it, that may also give you clues.
Did u find the solution? I habe the same problem.