What you can add to get more storage space

You have three main ways to add storage to a PC: install a second hard drive or solid-state drive inside the case, connect an external drive through a USB port, or use cloud storage on the internet. The fastest and most permanent solution is installing a drive inside your computer, but it requires opening the case and matching the right type of drive to your motherboard. External drives are simpler — you plug them in and they work — but they're slower and you have to keep them connected. Cloud storage is convenient for files you access from multiple devices, but it costs money each month and depends on your internet speed.

Most people choose internal installation if they want to keep large files like photos, videos, or games on their computer permanently. External drives work well if you need to move files between computers or want a backup you can unplug and store safely. Cloud storage makes sense if you mostly need access to documents and don't want to manage physical hardware.

Key Takeaways

  • Internal drives (SSD or HDD) are fastest and cheapest per gigabyte, but require opening your PC and matching the connection type your motherboard supports.
  • External drives plug into any USB port and work immediately, but are slower than internal drives and must stay connected to be useful.
  • Before buying any drive, check your motherboard manual or use CPU-Z software to see which connection types your PC supports — SATA, NVMe M.2, or USB.
  • Solid-state drives (SSDs) are faster and more reliable than traditional hard drives (HDDs), but cost more per gigabyte of storage.
  • If you're uncomfortable opening your PC, an external drive is the safest option and requires no technical skill beyond plugging in a cable.

Installing a drive inside your PC

Opening your computer case and installing an internal drive is the most effective way to add storage. Before you buy anything, you need to know what connection types your motherboard supports. The most common are SATA (an older standard that's still very common), NVMe M.2 (a newer, faster standard that looks like a small stick), and USB-C or Thunderbolt (less common for internal drives). You can find this information in your motherboard manual, or download and run the free software CPU-Z, which will show you every connection type your system has.

Once you know what your motherboard supports, buy a drive that matches. A 1TB SSD typically costs between $50 and $100, while a 1TB hard drive costs $30 to $60 but is slower. SSDs have no moving parts and are much faster for everyday use, so they're the better choice unless you're storing massive video files and need the lowest cost per gigabyte.

To install the drive, shut down your PC completely, unplug the power cable, and press the power button once to discharge any remaining electricity. Open the case — most have two thumbscrews on the back or a side panel that slides off. For a SATA drive, slide it into an empty SATA slot on the motherboard (they're usually near the edge of the board) and secure it with the bracket and screws that came with your case. For an NVMe M.2 drive, locate the M.2 slot on your motherboard (check the manual if you can't find it), remove the small screw, insert the drive at a 30-degree angle, then press down and tighten the screw. Plug the power cable back in, close the case, and power on. Your PC should recognize the new drive automatically.

Using an external drive

An external drive is the simplest option if you don't want to open your PC. You buy a drive in an external enclosure, plug the USB cable into any available USB port on your computer, and it appears as a new drive letter in File Explorer (Windows) or Finder (Mac). No installation, no opening the case, no matching specifications. The trade-off is speed — external drives connected through USB 3.0 are noticeably slower than internal drives, and you have to keep them plugged in whenever you want to use the files on them.

External drives come in two types: portable drives (about the size of a phone, powered through the USB cable) and desktop drives (larger, with their own power adapter). Portable drives are convenient for moving between computers or taking with you. Desktop drives are cheaper per gigabyte and slightly faster, but they need a power outlet and take up desk space.

When you buy an external drive, make sure it has a USB 3.0 port or newer (USB 3.1 or USB-C are faster). Check the product listing or the back of the box — it will say "USB 3.0" or "USB 3.1" or show a blue port. Avoid anything that only says "USB 2.0" because it will be very slow. A 2TB external drive typically costs $50 to $80.

Understanding drive types: SSD versus HDD

A solid-state drive (SSD) has no moving parts — it stores data on memory chips similar to what's in a phone. SSDs are much faster than hard drives, use less power, and are more reliable because there's nothing mechanical that can break. They're the standard choice for new computers and the best upgrade for an older PC. The main disadvantage is cost: SSDs are more expensive per gigabyte than hard drives.

A hard disk drive (HDD) uses a spinning metal disk and a moving arm to read and write data, similar to a record player. Hard drives are slower than SSDs, especially when your computer is starting up or opening large files. They do cost less per gigabyte, so they're still useful if you need to store huge amounts of video, photos, or backups and don't need fast access to those files. Many people use a small SSD for their main drive (where Windows or Mac lives) and a large hard drive for long-term storage.

For most people, an SSD is the better choice. A 1TB SSD costs about $70 to $100 and will feel noticeably faster than a hard drive. If you're on a tight budget and only need to store old files you rarely access, a hard drive is acceptable, but you'll notice the speed difference.

Checking your PC's current storage and capacity

Before you buy a new drive, check how much storage space you actually have and how much you're using. On Windows, right-click the C: drive in File Explorer, select Properties, and look at the pie chart. It shows your total capacity and how much is used. On Mac, click the Apple menu, select About This Mac, then click Storage. If you're using more than 80 percent of your drive, adding storage will help your computer run faster because Windows and Mac need free space to function smoothly.

Also check how much space you have available inside your case. Open the case and look for empty drive bays — rectangular slots where drives mount. Most modern cases have at least one empty bay. If your case is completely full, you may need to replace an existing drive instead of adding a second one, or use an external drive instead.

Connecting and formatting a new drive

After you install or connect a new drive, Windows and Mac will recognize it, but you need to format it before you can store files on it. Formatting erases any data on the drive and prepares it for use — this is normal and necessary the first time you use a new drive.

On Windows, open File Explorer, right-click the new drive, and select Format. Choose NTFS as the file system (the default option), give it a name if you want, and click Start. The process takes a few seconds to a few minutes depending on the drive size. On Mac, open Disk Utility (search for it in Spotlight), select the new drive from the list on the left, click Erase, choose Mac OS Extended or APFS as the format, give it a name, and click Erase.

After formatting, the drive is ready to use. You can move files to it by dragging and dropping in File Explorer or Finder, or by right-clicking a file and selecting Move To. If you're moving a large amount of data, the transfer speed depends on whether the drive is internal (fast) or external (slower).

Troubleshooting when a new drive doesn't show up

If you install a new drive and it doesn't appear in File Explorer or Finder, the most common causes are a loose cable, a drive that needs formatting, or a BIOS setting that needs adjustment. First, shut down your PC, unplug it, and check that the power cable and data cable are fully seated — push them in firmly until you hear or feel a click. Plug the PC back in and restart.

If the drive still doesn't show up, it may not be formatted yet. On Windows, open Disk Management (right-click the Start button and select Disk Management). You should see the new drive listed. If it shows as "Unallocated," right-click it and select New Simple Volume, then follow the wizard. On Mac, open Disk Utility and check if the drive appears in the list. If it does but isn't mounted, select it and click Mount.

If the drive doesn't appear in Disk Management or Disk Utility at all, it may not be detected by your BIOS. Restart your PC and enter the BIOS setup (usually by pressing Delete, F2, or F12 during startup — the key appears on the boot screen). Look for a setting related to SATA or storage devices and make sure it's enabled. If you're uncomfortable with BIOS settings, contact the drive manufacturer's support or ask for help in a PC building forum.

Frequently Asked Questions

Can I add a second drive without removing the first one?

Yes, most PCs have room for multiple drives. Check your case for empty drive bays and your motherboard for empty SATA or M.2 slots. You can install a second drive alongside your existing one without touching the first drive. Both will appear as separate drives in File Explorer or Finder.

What's the difference between a 2.5-inch and 3.5-inch drive?

2.5-inch drives are smaller and are typically used in laptops or portable external drives. 3.5-inch drives are larger and are standard for desktop PCs. Make sure you buy the size that fits your case. If you're buying an external drive, the size doesn't matter because it comes in its own enclosure.

Do I need to install drivers for a new drive?

No. Windows and Mac recognize standard SATA and NVMe drives automatically. You don't need to install anything. Just plug it in, format it, and it's ready to use. Some external drives come with software, but it's optional — the drive works without it.

Is it safe to move my files to the new drive?

Yes, but make sure the new drive is working properly first. Copy a few test files to it, restart your PC, and verify the files are still there. Once you're confident it's stable, you can move larger amounts of data. Never move your Windows or Mac system files to a second drive — keep your operating system on your original drive.

How much storage do I actually need?

It depends on what you store. Windows or Mac itself takes about 20 to 30GB. If you store photos and videos, plan for 100GB to 500GB depending on how many you have. Games can take 50GB to 150GB each. A good starting point is 500GB to 1TB for most people. You can always add more later.