Challenger is not detected by the Firmware loader software.
This is article is for when test pin 1 & 2 are linked and the firmware loader (V2.05.03523) is reporting No device attached.
The problem is caused by an incorrect driver loading in Windows.
Right mouse click My Computer select Manage.
Open the Device Manager,
Find the Challenger (may be under Ports),
Right mouse click the Challenger and select Update Driver,
Select Browse my computer for driver software,
Browse to location of firmware/firmware loader,
Tick the Include Sub-folders box,
The system may ask do you wan to load un-signed or unknown driver, select yes.
once complete reopen the firmware loader and the challenger should be there.