The three ways to add storage without replacing your drive

You can add storage to your PC in three ways: install a second internal drive, connect an external drive through USB, or use cloud storage. Internal drives are fastest and permanent. External drives are portable and work with any computer. Cloud storage lives on the internet and syncs across devices, but requires an active connection and a subscription for large amounts.

Which one you choose depends on what you need the storage for. If you edit video or work with large files, an internal drive is usually best. If you travel or need to move files between computers, external is simpler. If you just need backup or occasional access to old files, cloud storage costs less upfront.

Before you buy anything, check what your PC can physically hold. Open File Explorer on Windows or Finder on Mac, right-click your main drive, and select Properties or Get Info. Write down how much space you have left. Then open your PC's case or check your manual to see whether you have an empty drive slot. A laptop usually has room for one more drive; a desktop tower often has two or three empty slots.

Key Takeaways

  • Internal drives are the fastest option and stay in your PC permanently, but require opening the case and matching the right drive type to your motherboard.
  • External drives connect through USB and work when ready without installation, but are slower than internal drives and can be lost or damaged.
  • Cloud storage requires a monthly or yearly subscription and an internet connection, but lets you reach your files from any device.
  • Check your remaining space and available slots before buying, because a full drive slows your PC and not all drives fit all computers.
  • Installing an internal drive takes 15 to 30 minutes and requires only a screwdriver; if you are uncomfortable opening your PC, an external drive is safer.

Installing an internal drive: what you need to know first

An internal drive sits inside your PC case and connects directly to your motherboard. It is faster than external storage because data does not have to travel through a USB cable. Internal drives also do not take up desk space and do not need their own power cable (in most cases).

Before you buy, you need to know two things: what type of drive your PC uses, and whether you have a free slot. Most modern PCs use either a 2.5-inch SSD (solid state drive) or an M.2 NVMe drive, which is a small stick about the size of a stick of gum. Older PCs might have a 3.5-inch hard drive. Check your PC's manual or search the model number online to find out which one you have.

Next, look inside your case. You will see your current drive mounted on a bracket or tray. If there is an empty bracket or tray next to it, you can add a second drive of the same type. If there is no empty slot, you can still add storage, but you will need to replace your current drive instead of adding to it — which is more complicated and risky.

Buy a drive that matches your current one in type and size. A 1 TB or 2 TB SSD costs between $50 and $150 depending on the brand. NVMe drives cost about the same. Avoid the cheapest brands; stick with Samsung, Crucial, Kingston, or Western Digital, which have good track records.

How to physically install an internal drive

Shut down your PC completely and unplug it from the wall. Wait 30 seconds. This drains any remaining power and prevents damage to your components. Open the case by removing the side panel — usually two or four screws on the back. Set the screws somewhere you will not lose them.

Locate the empty drive slot. For a 2.5-inch SSD, you will see an empty bracket with four screw holes. For an M.2 NVMe drive, you will see an empty slot on the motherboard that looks like a thin horizontal slot. For a 3.5-inch drive, you will see an empty cage or bay.

For a 2.5-inch SSD: Slide the drive into the bracket so the screw holes line up. Screw it down with the four small screws that came with your drive or case. Do not overtighten — snug is enough.

For an M.2 NVMe drive: Locate the M.2 slot on your motherboard (check your manual if you cannot find it). Remove the small screw and standoff if present. Insert the drive at a 30-degree angle into the slot, then press down and screw it in place. The drive will sit flat against the motherboard when fully seated.

For a 3.5-inch drive: Slide the drive into the bay and screw it down on both sides. Make sure the power and data cables are not pinched underneath.

Close the case and plug the PC back in. Turn it on. Windows or Mac will recognize the new drive automatically. You may see a notification asking you to format it — this prepares it for use. Right-click the drive in File Explorer or Finder and select Format. Choose NTFS on Windows or Mac OS Extended on a Mac. Give it a name and click Format. The process takes a few seconds.

Using an external drive: the simpler option

An external drive is a hard drive or SSD in a protective case that connects through USB. You plug it in, and it shows up on your desktop or in File Explorer when ready. No installation, no opening your case, no risk of damaging internal components.

External drives are slower than internal ones because USB has a narrower pipeline than the connection inside your PC. A USB 3.0 external drive transfers files at about 100 to 150 megabytes per second. An internal SSD transfers at 500 to 3,500 megabytes per second depending on the type. For everyday use — copying photos, storing documents, backing up files — the difference is barely noticeable. For video editing or moving huge files constantly, it matters.

Buy a USB 3.0 or USB 3.1 external drive, not USB 2.0, which is much slower. A 1 TB external drive costs $40 to $100. Brands like Seagate, Western Digital, and LaCie are reliable. Plug it into any USB port on your PC. If your PC asks whether to format it, say yes. Then drag files onto it like you would any folder.

External drives are also portable — you can unplug them and take them to another computer. They are good for backups, for moving large files between machines, or for keeping old projects you do not need every day. The downside is they can be lost, stolen, or damaged if dropped. Keep important files in two places.

Cloud storage: access your files from anywhere

Cloud storage keeps your files on a company's servers instead of on your PC. You upload files through an app or website, and you can read them from any device with an internet connection. Popular options include Microsoft OneDrive (comes free with Windows), Google Drive, Dropbox, and iCloud (for Mac).

Most cloud services give you 5 to 15 GB free. If you need more, you pay a monthly subscription — usually $2 to $10 per month for 100 GB to 2 TB. The advantage is you never run out of space on your PC, and your files are automatically backed up. The disadvantage is you need an internet connection to reach them, and your files live on someone else's servers.

Cloud storage is best for documents, photos, and small files you want to access from multiple devices. It is not ideal for video editing or large projects, because uploading and downloading gigabytes takes a long time. Set up cloud storage by downloading the app for your service, signing in with your account, and choosing which folders to sync. Files then upload automatically whenever you save them.

Combining storage methods for the best setup

Most people use all three methods together. An internal SSD holds your operating system and programs, keeping your PC fast. An external drive backs up important files weekly. Cloud storage syncs documents and photos so you can reach them from your phone or another computer.

Start with an internal drive if your PC has a free slot and you are comfortable opening the case. Add an external drive for backups — set it to run automatically once a week. Use cloud storage for files you need on the go. This way, if one storage method fails, your files are safe in another place.

Check your storage space once a month. Open File Explorer or Finder, right-click your main drive, and look at how much space is left. If you are below 10 percent free space, your PC will slow down noticeably. Delete old files, move them to external storage, or add another internal drive.

Frequently Asked Questions

Will adding a second internal drive slow down my PC?

No. A second internal drive does not affect your PC's speed. Your operating system and programs run on your main drive, and a second drive is just extra storage. The only exception is if your main drive is completely full — then your PC slows down because it has nowhere to write temporary files.

Can I use an external drive as my main drive?

You can install Windows or Mac on an external drive and boot from it, but it is slower than using an internal drive and the connection can be unreliable. External drives are better for storage and backup than for running your operating system.

What happens if I unplug an external drive while files are copying?

The files being copied will be incomplete or corrupted. Always wait for the copy progress to finish and the drive to stop blinking before unplugging. On Windows, right-click the drive and select Eject first. On Mac, drag it to the Trash.

Is cloud storage safe for sensitive files?

Major cloud providers like Microsoft, Google, and Dropbox encrypt your files and have strong security. Your files are safer in the cloud than on a single external drive that could be stolen. For extremely sensitive documents, use cloud storage with two-factor authentication enabled.

How much storage do I actually need?

If you store mostly documents and photos, 500 GB to 1 TB is plenty. If you edit video or keep large game libraries, 2 TB or more is better. A good rule is to buy twice as much as you think you need — storage always fills up faster than expected.