Creating System Image Fails every time - Run CHKDSK /R

Hi All

I want to create a system image on my NTFS formatted portable WesternD HDD. Now It has about 250GB of space left(the portable HDD), and the Laptop PC that i want to create the image of, tells me I need about 199GB for the system image.
Then first time I created the image, it gave me a failure message saying I should run a CHKDSK /R and ty again. I ran a CHKDSK /R on the external drive and tried making a system image again, where it got about halfway and gave me the same message. What is going wrong every time?

Also, when I eventually successfully manage to make a system image, can I use that image to restore my PC should it crash or go haywire or should I make a System repair disk as well, or are those two separate from each other?

Thank You

I'm not an expert at anything so here's what I think I know. :)

Your last question first: A system repair disk is not the same as a system image. The repair disk allows you to boot your computer so you can access various repair tools, one of which is to restore your computer using a previously made system image. If you can boot your computer normally, it's not necessary to use the repair disk to access a system image. This tutorial gives more info.

System Repair Disc - Create

As far as the chkdsk /r message, that sometimes indicates a hard drive might be failing or there are too many damaged sectors on the drive for it to be used successfully. Perhaps someone with more experience will jump in, but if it was me, I'd try to create a system image using a free imaging tool like Macrium Reflect.

Macrium Reflect FREE Edition - Information and download

If Macrium can't create a system image the chances are pretty good that the WD hard drive is at fault. But if the image CAN be made using Macrium, you may have some other problems related specifically to the Windows 7 imaging tool files. Perhaps they became damaged or corrupt somehow. You could run a System File Checker scan from an elevated command prompt (option two.) If problems are found run the scan 3 times rebooting in between each scan.

SFC /SCANNOW Command - System File Checker

Another thought is even though you have 250GB of free space on the WD and the system image will only require 199GB, I just don't know for sure if that's enough hard drive space for a 199GB image. But if you have access to a different HD with more free space, it might make a difference. Likewise, using all the default settings in Macrium will compress the system image from 199GB down to about 125GB or so. And this compression may provide enough free space for the system image to be made. But like I said, I'm really not sure on this.

@marsmimar: Thank you very much, I appraciate your help. Will definitely try the Macrium option.

@Karlsnooks: The first time I ran CHKDSK on the External, it came up with no errors, however, when I ran the CHKDSK on the LAptop's harddrive, it had a few bad clusters which was repaired. I haven't tried the backup again after doing the dhkdsk, so maybe I should give it another try? So you say if Windows has problems creating the image, so will any other software? Thank You for your help