Migration Assistant cannot find ext drive
I have a clean iMac running El Capitan. The iMac is about 4 years old. I want to load data from a PC and I backed up the PC data on an external drive. Now when I USB the external drive on the iMac and run Migration Assistant, it just spins looking for the ext hard drive. The HD even shows on the monitor but it cannot seem to find it???
Any suggestions? There are 4 folders in the ext drive - what should I do? Thanks
JIM
iMac, OS X El Capitan (10.11.6), Belongs to a friend - not my person