OK, some good advice and some misaimed advice was given so far. Here is how the whole "old OS + new drive" thing breaks down:
1) Above 2 TB the drive needs to be formatted with a GPT instead an MBR partition table to see the whole disk (without special software*) regardless the OS.
2) Windows XP (32-bit) doesn't support GPT... et all (without special software*).
3) Windows Vista and later MS OS-es support GPT properly.
4) To *boot* from a drive formatted with a GPT partition table, your system needs to be UEFI compatible.
5) Accessing a drive formatted with GPT can be done on a system using BIOS, provided the proper OS (or special software*) is used.
*I've used such software with my first 4K sector size, 2TB+ drive. IIRC it was a WD drive with vendor supplied software to access the 2TB+ part of the drive on Windows XP. My experiences can be summed up as "just don't bother".
My advice is to focus on backing up your data first, *then* try and figure out how you want to reconfigure your system. For that purpose using one of the myriad "live disc/live USB" options should suffice. This could even be Windows PE on a disc made using a Windows 7 install disc, or use any Windows 7/8, etc. install disc (which are running in their own Windows PE environment), press F10 and you should get a command prompt and access to all the drives currently connected to the system.
Once your data is backed up you can try and clone the system, do a clean reinstall, dual-boot, whatever, but things will be a lot *less* hair-raising when you know you can undo things with your backup.
EDIT:
If you're worried about NTFS files with special permissions or want to preserve the ACL (Access Control List) of the files, or better yet, *the whole boot partition*, I suggest you familiarize yourself with the tool MS made for the task, ImageX.
It's a file-based back-up tool, so unlike sector-based tools like Norton Ghost you won't run into weird problems because the hardware (or its sector size or offset) is different. Sysops use it as part of mass-deploying various tweaked version of the OS, so it *should* handle most vagaries of how MS filesystems are tweaked. (Mostly uncrawlable symbolic links for win32 compability and other hacks). It can only back-up partitions, not whole disks, but you *can* tweak what it saves from said partition. (I think you'll mostly want the old user profiles just in case).
https://technet.microsoft.com/en-us/library/cc722145%28v=ws.10%29.aspxAnother useful tool from MS is called robocopy, a mass file-copier. If all you want is to back up data, it's superb. Unfortunately it can't handle the above mentioned special symbolic links well. (Though IIRC, those only came into vouge with Windows Vista).