Why can't I have a partition bigger than 2TB?
While you connect a new disk to your computer, Windows will ask you to initialize it. You can choose MBR (Master Boot Record) or GPT (GUID Partition Table) as its partition style. The maximum size of an MBR disk is 2TB (Terabytes) and it can hold up to 4 primary partitions. Unlike MBR disk, GPT disk doesn’t have such limitations. The maximum size for a GPT disk depends on the operating system (some previous versions of Windows like Windows XP/Vista cannot recognize GPT partition style) and file system.
The most common file systems used in Windows are NTFS and FAT32. FAT32 is the older one of the two file systems, which was created in 1977 by Microsoft. It can be used in many other operating systems (OS) besides Windows. However, it supports up to 2TB volume size and 4GB file size. If you have files bigger than 4GB or want to have a partition beyond 2 TB, you need to reformat the partition as NTFS. NTFS is the newer one introduced in 1993, which seems to work only with Windows. The maximum partition size of NTFS depends on the smallest cluster size. NTFS maximum size = cluster size * (2^32 -1). By default, the cluster size is 4096 bytes, so its limit is 16TB. Therefore, to break 2TB file system limit, you can convert the disk to GPT disk and format it as NTFS.
Break the volume size barrier with built-in utility
Disk management is the Windows built-in utility for managing your disks and partitions. Disk Management can only convert completely empty disk to GPT disk, so you’d better backup disk before conversion. To launch Disk Management, You can type “diskmgmt.msc” in the search box and press Enter.
1. Delete all the partitions on the disk you want to convert.
2. Right click the empty disk and select Convert to GPT Disk.
3. Right click the unallocated space and select New Simple Volume. Then follow the wizard to create volume beyond 2TB, and it will select the NTFS file system as default.
Note that if you want to reinstall Windows on a GPT disk, the motherboard has to support UEFI Boot Mode, and UEFI boot mode must be enabled after the conversion.
Another advanced method
If you do not want to get all the data on that disk wiped out, you can use AOMEI Partition Assistant Standard, a freeware works for Windows 10/8.1/8/7/XP/Vista, to convert disk to GPT without data loss.
2. Right click the disk and select Convert to GPT disk.
3. Click Apply to execute the operation.
4. Right click the existing partition and select Resize Partition to extend the partition using the unallocated space. Then follow the instruction to expand 2TB partition, and don’t forget to click Apply in the end of your operation.
If the partition is formatted with FAT32, you can click NTFS to FAT32 Converter to convert FAT32 to NTFS without affecting the data on the partition. Besides using AOMEI Partition Assistant to break 2tb file system limit, you can also use it to Migrate OS to SSD, Copy Disk, make bootable media, create Windows to Go disk, and more.