It is definitely do-able,
Make sure that the two Hard drives match in capacity, or that the new one is larger than the original, and that both hard drives will remain in the same computer. (if they don't, windows might throw a fit, and that would also be piracy )
put both hard drives in the machine and make sure that your BIOS has enabled them (press one of the "F" keys to setup your BIOS during boot) Boot gparted, and when you can see both hard drives in gparted, right click the partition with the working windows install, and select copy. then in the drop down menu, select your new hard drive, click and select paste.
Depending on the size of your drive, it may take anywhere from an hour, to overnight.
If your copy doesn't boot, boot up off a windows xp CD, and run "chkdsk /f" at the recovery console (let the CD load, and press "r" when prompted if you want to install XP)
I hope this helps, and please report back to the forum for any problems, or if you get it working.