Clone a disk - not enough space error

I am trying to clone my 750GB drive onto a new external 750GB HD.

The internal SATA drive still has more than 50% capacity free so there is ample room on the destination external 750GB drive.

I keep getting an error though that there is not enough room on the external drive and a suggestion to try some 'manual' options instead of the Clone Wizard. I've tried some manual options and nothing is working.

I've attached a screen grab of both dialogue windows as a JPG.
Cheers

 

Have you run chkdsk yet?

 

Your references to ample space and capactity are confusing to me. Cloning will wipe everything off the destination drive so destination drive will match the source drive. Two identical drives will be the result.

Cloning / Imaging Terminology: (extracts from Acronis Support postings)
Clone Disk - When you use the "Disk Clone" tool, you effectively copy/move all of the contents of one hard disk drive onto another hard disk drive. This function allows you to transfer all the information (including the operating system and installed programs) from a small hard disk drive to a large one without having to reinstall and reconfigure all of your software. The migration takes minutes, not hours,
but it is not generally used as a backup strategy.
Backup - (Imaging) creates a special archive file for backup and disaster recovery purposes--which
also includes new drive replacement. Single partitions or entire drives can be imaged for use as
partition or drive replacement. Archive file can be created within Windows mode or from Acronis
bootable Rescue CD. Archive files can be stored in folders and/or alternate drives or media.
If interested in backing up your hard drive for the disaster recovery purposes, the Backup approach is
recommended. Moreover, there are several advantages of creating an image over the disk cloning
procedure such as: you can create an image without rebooting your PC, image creation can be
scheduled for the particular point in time, Acronis True Image allows you to create incremental and
differential images, image archive contains only the actual data and so it has a smaller size, images
are ordinary files and so they can be stored on any type of the supported media, etc.​

As SparkyMachine has indicated, have you performed error checking on both drives?

 

I'd do a surface scan of both drives, either CHKDSK or the drive manufacturers utility.

If all you want to do is clone the internal to the external drive, the drive manufacturer utility can clone a drive very nicely.