Windows 7 32-bit or 64-bit versions can read large drives (>2TB) without any additional software.
To boot from large drives (>2TB) requires UEFI boot and Windows 7 64-bit.
If you plug any drive formatted with NTFS (default Windows 7 file system) or FAT-32 (older file system still used with USB keys sometimes) into a Windows machine, it will be automatically recognised. When you reinstall the operating system, the drive will still be recognised.
Usually new hard drives come with a partition configured and a default NTFS format. It's surprising that yours did not, but all you had to do to create this partition is run the disk manager in Windows 7.
Click the Start button
Enter "computer" in the Search programs and files bar.
Click "Computer Management"
Under Storage, click "Disk Management"
You can see all your disks and partitions here as well as volume types and file system types.
You can keep using your drive without any problems