Can I unplug an external HD...

[DrClovis]

My back up transfer is frozen as is my imac.
Any ideas?
thanks
DrClovis

 

[gullySn0wCat]

Yes. Reboot and try again.

 

[AppleNewton]

The drive may be causing the iMac to hang, so unplug the drive reboot the iMac and open Disk Utility from the Applications > Utilities folder , select the External Hard Drive and click repair disk (it will verify to make sure it is not corrupt and if its all good to go it wont alter anything with the drive itself).