I want to move everything from my old C drive (20G) to a newer/bigger C drive (120G), including XP Pro OS, so that my computer doesn't notice the change/move.

Software suggestions???

   Several years ago some of the harddrive manufacturers sent software with new harddrives (and some were available on their websites) which would transfer everything over.  It has been a while since I have seen them around so I don't know if the harddrive manufacturers still provide that software.
   What the software does and what you want to do is copy the image of the old drive over to the new drive.
   So any software that copies or backs up the image of the drive should be able to do that.  I have DriveImage XML (which is freeware) and it seems like it would do that, even though sometimes it has given me problems.
   What you would do is turn off the computer, hook up the harddrive on one of the available cables, turn on the computer, verify that it recognized the new drive (make sure that it shows it as the correct size too), fdisk or partition the new drive, use the software to copy the image of C to the new drive, turn off the computer, take the old drive off, connect the new drive on the cable where the old one was (make sure that the master/slave switch is on the same setting), and that should do it.

Thanks, Ray.  I have been leery of the quick transfer on the free software of a new drive.  I guess I was looking for a more complicated piece of software. (hi-hi)

Acronis makes a great program for cloning your disk. Its not overly expensive and works great for backups as well.
If you purchased a Seagate drive, they offer a branded version of this that is available for download and it is free. Google Seagate Disk Wizard and you will find it.