What adding storage means and why you might need it

Adding storage to your PC means installing a new drive — either a hard disk drive (HDD) or a solid state drive (SSD) — so you have more room to save files, programs, photos, and videos. Your computer comes with one drive built in, and once that fills up, programs slow down, you can't save new files, and Windows itself starts to struggle.

You don't have to replace the drive you have. You can add a second drive alongside it, keep both, and use them together. This is the route most people take because it's cheaper and less risky than swapping out the original drive.

How much storage you need depends on what you do. If you mostly browse the web and use email, 256 gigabytes is plenty. If you edit video, store large photo libraries, or keep years of documents, you might want 1 or 2 terabytes. One terabyte equals 1,000 gigabytes.

Key Takeaways

  • You can add a second drive to most PCs without removing the original one, which is safer and cheaper than replacing it.
  • SSDs are faster and more reliable than older hard drives, but cost more per gigabyte — most new drives sold today are SSDs.
  • The type of drive you can add depends on your PC's motherboard and available slots, which you can check in Device Manager or by opening the case.
  • Installation takes 10 to 30 minutes and requires only a screwdriver and the drive itself; you do not need special software or technical knowledge.
  • After you install the drive, Windows will recognize it automatically, but you must format it before you can save files to it.

SSD versus HDD: speed, cost, and what to buy today

An SSD (solid state drive) has no moving parts — it stores data on memory chips, the same way a USB stick does. An HDD (hard disk drive) uses spinning magnetic platters, like a record player. SSDs are 5 to 10 times faster, produce no noise, and last longer. They also cost more per gigabyte, though the price gap has narrowed in recent years.

If you are buying a new drive today, an SSD is the better choice for almost any use. A 1-terabyte SSD costs between $60 and $120 depending on the brand and speed. A 1-terabyte HDD costs between $40 and $70, but the speed difference means you will notice the slowness every time you open a large file or move data around.

The only reason to buy an HDD now is if you need very large storage — 4 or 8 terabytes — and cost is your main concern. Even then, many people buy two smaller SSDs instead, because the speed gain is worth it.

Check what type of drive your PC can accept

Your motherboard determines what kind of drive you can add. Most PCs built in the last five years have at least one M.2 slot, which is the fastest and easiest option. Older PCs might have only SATA slots, which are slower but still common. A few very old machines have only IDE, which is rarely worth upgrading.

To find out what your PC has, open Device Manager on Windows by right-clicking the Start menu and selecting "Device Manager". Look for "Drives" in the list. You will see your current drive listed — if it says "NVMe" or "M.2", your PC has an M.2 slot. If it says "SATA", you have SATA slots.

You can also open your PC case and look inside. An M.2 drive looks like a thin stick of gum, about 2 inches long, and plugs into a small slot on the motherboard. A SATA drive is a flat rectangle about the size of a paperback book, and connects with two cables — one for power, one for data. If you are not comfortable opening the case, you can ask a friend or take it to a local computer repair shop for five minutes.

M.2 drives: the easiest option for most PCs

If your PC has an M.2 slot, this is the route to take. M.2 drives are small, fast, and require no cables. You push the drive into the slot at a 30-degree angle, then press down until it clicks, and you are done. The whole process takes two minutes.

When you buy an M.2 drive, make sure it says NVMe on the box — that is the protocol that makes it fast. Older M.2 drives exist that use SATA protocol instead, and they are no faster than a regular SATA drive. Most drives sold today are NVMe, but check the label to be sure.

You do not need to install any drivers. Windows will recognize the drive the moment you restart your PC. You will then need to format it — right-click the drive in File Explorer, select "Format", give it a name, and choose NTFS as the file system. After that, you can save files to it when ready.

SATA drives: the older but still reliable option

If your PC has only SATA slots, you can still add storage, but the process is slightly longer. You will need to mount the drive in an empty bay inside your case, then connect two cables — one to the motherboard, one to the power supply.

SATA drives come in two sizes: 2.5 inches (the size of a thick credit card) and 3.5 inches (the size of a paperback book). Most modern PCs have 3.5-inch bays, but check your case before you buy. The drive itself does not care which size — the speed is the same. The 2.5-inch versions are just older and less common now.

After you install the drive and restart, Windows will see it, and you format it the same way as an M.2 drive. SATA drives are slower than NVMe, but still much faster than the HDDs from ten years ago, and they are reliable if you buy from a known brand like Western Digital, Seagate, or Crucial.

Installation step by step

Before you start, shut down your PC completely and unplug it from the wall. Touch a metal part of the case to discharge any static electricity from your hands — this protects the drive from damage.

For an M.2 drive: Open the case. Locate the M.2 slot on the motherboard — it is usually near the CPU or along the edge. Remove the small screw at the end of the slot if there is one. Hold the drive at a 30-degree angle and slide it into the slot until you feel resistance. Press down gently until the drive is flat and the screw hole lines up. Replace the screw. Close the case.

For a SATA drive: Open the case. Locate an empty 3.5-inch bay — these are usually stacked vertically on the front or side of the case. Slide the drive into the bay until the screw holes line up. find it with four screws, one on each side. Locate the SATA power cable from the power supply — it has a flat L-shaped connector. Plug it into the back of the drive. Locate a SATA data cable connected to the motherboard. Plug the other end into the back of the drive. Close the case.

Plug the PC back in and turn it on. Windows will detect the new drive automatically. You do not need to restart, though restarting makes the drive appear faster in File Explorer.

Format the new drive so Windows can use it

A brand-new drive is blank and unformatted. Windows can see it, but you cannot save files to it until you format it — this creates the file system that tells Windows how to organize data on the drive.

Open File Explorer and look for the new drive in the left sidebar. It will show as a drive letter with no name, usually "D:" or "E:" if your original drive is "C:". Right-click it and select "Format". A window will appear asking for a name — type whatever you want, like "Storage" or "Backup". Leave the file system set to NTFS. Click "Start" and confirm the warning. The format takes a few seconds to a few minutes depending on the drive size.

After formatting, the drive is ready to use. You can now copy files to it, install programs on it, or set it as the location where Windows saves downloads and documents.

Frequently Asked Questions

Do I need to reinstall Windows after adding a new drive?

No. Windows stays on your original drive and works exactly as before. The new drive is just extra storage. You do not need to reinstall anything or change any settings.

Can I add a drive if my case is full?

If you have no empty bays for a SATA drive, you have two options: buy an external USB drive instead, or replace your current drive with a larger one. An external drive is slower but requires no opening of the case. Replacing the drive is faster but more involved and means backing up your files first.

What brand of drive should I buy?

Western Digital, Samsung, Crucial, and Seagate are the most reliable brands. Avoid very cheap no-name drives from unknown sellers. A mid-range drive from a known brand costs $10 to $20 more and will last years longer.

How do I know if my drive is failing?

Signs include clicking or beeping sounds, files taking much longer to open, or Windows freezing for seconds at a time. If you hear clicking, shut down when ready — continuing to use the drive can make the problem worse. Back up your files to another drive or cloud storage as soon as you can.

Can I use the new drive to back up my original drive?

Yes. After you format the new drive, you can use Windows Backup or a free tool like Macrium Reflect to copy everything from your original drive to the new one. This takes an hour or more depending on how much data you have, but gives you a complete copy in case the original drive fails.