Kalle- I had one of those external drive enclosures, I used the ribbon cable from it for something else and without that cable it's pretty much useless. Like you say they are inexpensive to buy. Maybe I can make it work that way if I buy another one and the usb doesn't work.
 
Thanks guys for your help...I'll determine if my computer will see my usb drive and experiment with my boot CD. If the computer doesn't see the usb drive image then it's go to plan B.If all goes as planned I should be able to do it without a lot of trouble. 
 
I have a few serious things to do on the computer, I probably should wait until after I do them.If something goes funky I'm in trouble.

Starise
Kalle- I had one of those external drive enclosures, I used the ribbon cable from it for something else and without that cable it's pretty much useless.

Mine is USB. I can plug in any of my removed HDDs any time I want. 

I've done the overwrite or put in the new C drive lots of times with Acronis. I have Acronis True Image 2013..

Basic steps.

1. Back up to an external drive your whole C drive with Acronis. Might want to do that to two external drives just to be safe in case your one external drive hiccups.

2. Shut down replace your physical c drive.

3. boot from the Acronis CD that comes with Acronis

4. Restore drive from backup with Acronis

It's remarkably straightforward. Just a couple mouse clicks all told for the whole cycle there.

Lawajava...I sure hope my change out goes just as smoothly as that. This is what I am hoping for... 

I made the change on my C drive yesterday with minimal problems. I wanted share what I came across in case anyone else is looking at doing the same thing.
 
First I tried restoring to my new drive installed in my old drive location and using my usb connected HDD as a backup with Acronis 2013 and an image on that drive. Before hand I made a backup disk in Acronis and had my computer boot off of it.....no banana....my computer never seen my boot disk. 
 
Plan B: I disconnected one of my data storage drives and connected my new HDD to that location. I then simply told Acronis  to make a clone of my C drive. After the clone was completed I exchanged places with it removing my old C drive,reconnecting my data drive and putting the clone where the old C drive had been. The computer booted up like nothing had ever happened and I felt like I had my old friend back...plus an extra TB of data. This has been my first experiences with a Seagate drive....I should probably make a copy right away as I've heard some scary things about Seagate drives.
 
Clones are  better IMO than images. Images need to be rebuilt from a compressed file while clones don't. To me it seems like a backup image is like the secondary parachute when the first one fails...I'm not totally confident of it. In my case the backup failed me because my computer wouldn't see the boot disk. In the event I couldn't make a clone, my only recourse would have been to remove the drive from the usb enclosure and attempt to hook it through SATA, and then hope that the image would be recognized.