How to boot from an alternative harddisk drive ?

The only way to make it bootable is to use a utility like Acronis True Image to make an exact clone of the disc.

What should I do to boot from it?

You'd just need to make it the 'primary' drive (in the BIOS).

I added a second internal hard disk(250Gb) and copied my C-drive to it...

Since you specifically mention Norton Ghost, I assume you mean you created an image of C:\ :emotion-55:

Question 2: Is going for RAID1 a feasable/sensable option? If yes, what should I do to implement it?

RAID 1 is certainly both a feasible and a sensible option.

But you need to use two hard drives of the same capacity for starters.

And you're best to start with a clean sheet - i.e. reinstall the OS, drivers, windows updates, applications, games etc?

It would appear setting up a RAID 1 array to an existing install can be done.

But that's on a Nvidia board setup - and using a Nvidia BIOS which supports striping on a single drive - initially.

And this suggests it can also be done, by setting the drives up as a "broken array", and letting it "rebuild" (approx time to rebuild 1TB is 12 hours!)

What you could do however... assuming you're 100% sure it's a working image... is borrow an external hard drive, and copy your image to it.

Then setup the two drives in your system in a RAID 1 array, and install the image off the external drive :emotion-55:

But starting from a clean install is definitely the best way to go IMO.

BTW:  You can buy external RAID enclosures nowadays. 

I personally have a Raidsonic Stardom SR3610-2S-SB2 (USB 2.0/eSATA) Raid Enclosure hooked up to each of my two gaming PC's (via eSATA) for backups :emotion-11:

They ain't cheap though :emotion-3:

But the cost is relative of course.  Can you put a price on all your important data/programs/files :emotion-55:

Thanks for your reply, Fireblade!!

Indeed, I used Norton Ghost12 for the C-drive copy. When I make it the boot device using PF12 during startup, it comes with the message "selected boot device not available". Also hard switching the two disks doesn't make it boot-able. 

The RAID1 implement doesn't seem an easy step to take, so I think I better stay away from it or buy an external RAID enclosure as you suggest.

Thanks husky0894 for your reply! So it is not going to work out with my Norton Ghost12 copy, I understand! I am not sure what the purpose is of that Ghost12 feature then!?!  If I make the copy with Acronis True Image, can I then use and operate the copied disk free space online for example for accomodating CS4 Photoshop work files?