Scott,
The easiest way is to use an image program to transfer the data or close the drive. You just need to make the new drive is larger than the other. The are several imaging programs out there (Google Imaging software), but the one I use and prefer is Acronis. It's newest version is Acronis True Image Home 2009. You simply can't go wrong with Acronis. Symantec makes Ghost, but you simply can't go right with Symantec.
You can do it directly from DOS, but it CAN BE more complicated, and I wouldn't recommend it. Also, if you are using WD hard drives, it comes with software to image the drive right over.
It is important to know if you are transferring IDE to IDE (the large grey ribbon like cables) or SATA to SATA (the newer smaller cables with the black ends), or a variation. Most likely if it is a variation, it would be IDE to SATA. They make some cables and hardware that allow you to connect via different connections if needed, even USB.
The whole process is rather straightforward. You just want to make sure you don't do anything to the old drive until you know the new one is working and bootable and has all the data. To that end, I would probably make a separate backup to an external drive or DVD if you can. Acronis will do the backup too. By the way, you will end up with great backup software with Acronis.
Alternatively, you could just reinstall the OS and transfer the data, but you would have to reinstall all your programs.
After rereading your question, I hope I am not misunderstanding what you want to do. I am assuming you want to transfer the data including the OS from the old drive to the newer one. If you simply want to move the drive from the old machine to the new one that is simple.
Let me know which one you are trying to do, and I can walk you through it.
HTH
