can i do this?

[board2death986]

I have a single drive partitioned in two, a 500GB into partitions of 250GB each.

I have my OS and apps all installed on one partition, I was wondering if i cloned the drive to a second HDD, and reformatted the drive to a single partition, could I copy back the OS?

[firebane]

Yup Acronis will allow you to do that.

[pc299]

I forget which, but either Acronis or Partition Magic can merge two existing partitions... (I'd backup your data just in case) but theoretically you could merge the two partitions without any data loss.

[Old Hippie]

Acronis for the cloning and partition resizing while cloning jobs.
Partition Magic for doing anything with a partition.
If you're lookin' for free, I've been told Gparted (http://gparted.sourceforge.net/) is just as good as PM, but not as pretty.

[axan]

ya gparted can merge all your partitions into 1 without data loss, it's not as easy to use as partition magic but it is free.