How to Move Steam Games to Another Drive Safely

Your boot drive shows 41 GB free, a 93 GB update is queued, and Steam stops with a disk space error before it writes a byte. The usual response is to uninstall two games you still play, which buys about a week before the same message returns. The better move is to put part of the library on a second drive, and Steam has done that properly since the Storage Manager replaced the old folder dragging era.

I have reorganised libraries on five machines this year, including one with a 500 GB NVMe boot drive and a 4 TB SATA SSD added two years later. The built in tool handles most of the work in a few clicks. There are two situations where it quietly fails, and that is where people lose progress, so the order of operations matters more than the clicking.

Why the drive fills faster than you planned

Install sizes have outgrown the drives most prebuilts shipped with. A single modern open world title sits between 100 and 150 GB. Shooters with high resolution texture packs push past 200 GB. Three of those plus Windows, which wants 30 to 40 GB with its update cache, and a 1 TB drive is gone.

Steam also keeps a downloading folder inside steamapps while it patches. During a large update that folder can briefly hold almost a second copy of the changed files, which is why a 93 GB patch can need far more than 93 GB free. Workshop content adds more on top, and for mod heavy games it is easy to carry 20 GB of subscribed items you forgot about.

Shader caches are the quiet one. On my machine the shadercache folder had grown to 11.3 GB across nine games. It rebuilds on demand, so clearing it costs you one longer first launch per game and nothing else.

Moving a Steam library the supported way

This is the whole process, and on a wired internal SSD pair it takes minutes rather than a redownload.

1. Close every game and let Steam finish any download. A paused download still holds files open and the move will refuse to start.
2. Open Steam, then Settings, then Storage. The drive picker sits at the top. Everything in this screen refers to Steam libraries, not your whole disk.
3. Add a library on the new drive. Click the plus next to the drive dropdown, pick the drive, and Steam creates a SteamLibrary folder at its root. Keep the default path. Nested folders inside Documents or OneDrive cause permission trouble later.
4. Select the games you want to move. Tick the checkboxes in the list, which shows size per title. I move the biggest two or three first and stop there.
5. Click Move and choose the destination library. A progress bar appears with a transfer rate. NVMe to NVMe I see 900 MB/s to 1.4 GB/s, so a 120 GB game lands in two or three minutes. NVMe to a mechanical hard drive drops to roughly 150 MB/s, closer to fifteen minutes for the same game.
6. Launch the moved game once. Steam checks the files on first run. If a launcher or anti-cheat service needs reinstalling it happens here, not later when you are mid queue.

Steam writes a fresh appmanifest_[appid].acf in the new library and removes the old one. Nothing needs editing by hand, and no registry key has to change. If you have several storefronts installed, the same logic applies to each of them separately, which is one more reason to keep the clutter down; our notes on managing too many game launchers cover that side of it.

Where the built in mover gives up

Two cases send the Move button grey or make it fail partway.

Games that install outside steamapps. Titles with their own launcher or a third party redistributor sometimes park files in Program Files. Steam moves what it owns and leaves the rest, so the game still depends on the old drive. Check the install folder from the game properties, Installed Files, Browse. If the real content is elsewhere, uninstall and reinstall into the new library instead of moving.

A drive formatted as exFAT or a mapped network drive. Steam wants NTFS. ExFAT drives appear in the picker on some builds and then throw a write error at around 2 or 3 percent. An external USB SSD is fine if it is NTFS and connected directly rather than through an unpowered hub.

When the mover refuses and reinstalling is not realistic on your connection, copy steamapps\common\[Game Folder] and its matching appmanifest file to the new library with robocopy, then restart Steam. Use robocopy "D:\old\path" "E:\new\path" /E /COPY:DAT /R:2 /W:2 so a single locked file does not stall the whole job for half an hour. I have done this four times and it worked three times. The fourth needed a reinstall anyway.

What stays behind on the old drive

Moving a library moves the game, not everything around it. Saves for most titles live in %USERPROFILE%\Documents\My Games, %LOCALAPPDATA%, or inside steamapps\userdata, and those paths do not follow a library move. That is usually fine, since the move leaves them untouched, but it means a drive you plan to retire still holds your progress. Copy it out first; the folder list in our guide to backing up PC game saves is the one I work from.

Workshop files move with the game. Manually installed mods that were dropped into the game folder also move, but mod managers that store an absolute path in their config will point at the old drive afterwards and need the path updated once.

The advice I would skip

The common recommendation is to keep competitive games on the SSD and move single player games to a mechanical drive, because load times in a story game do not matter. I followed that for a year and changed my mind.

Load screens are not the problem. Streaming is. Open world games pull texture and geometry data continuously while you move through the map, and on a 7,200 RPM drive with 4 KB random reads measured in single digit MB/s, that shows up as texture pop in and a hitch every time you turn a corner fast. A story game stutters more than a round of a shooter that loaded one small map and then sits in memory. If I only had one SSD, the open world titles would stay on it and the competitive shooter would go to the hard drive.

The other line I would not repeat is that a drive performs fine until it is completely full. SATA SSDs lose write speed well before that, and I plan for 15 percent headroom rather than 10. On a 1 TB drive that is 150 GB kept clear, which sounds wasteful until a 93 GB patch arrives on a Thursday evening. If you want somewhere easy to claw space back from, the preinstalled software covered in removing bloatware from a new Windows PC is usually worth 8 to 20 GB.

A short check after the move

Launch each moved game once and let it reach the main menu. Then open Settings, Storage again and confirm the old library no longer lists those titles. If a game still appears in both places, the manifest did not get cleaned up, and verifying integrity of game files from the game properties fixes it in a minute or two.

Do one drive this week, not the whole library. Move your two largest games, play both for an evening, and only then move anything else.

FAQ

Can I move Steam games to another drive without redownloading?

Yes. Settings, Storage, tick the games and click Move. Steam transfers the files and rewrites the manifest, so nothing is downloaded again.

Will moving a Steam game delete my saves?

No. Saves usually sit in your user folder or in Steam Cloud and are not part of the library move. Back them up anyway before retiring the old drive.

Is it bad to install Steam games on an external drive?

It works if the drive is NTFS and plugged straight into a USB 3.0 port or better. A USB 2.0 port or an unpowered hub will cause disconnects mid session.

Do I need to reinstall Steam itself on the new drive?

No. Leave the Steam client where it is and add a second library. Only the game files need to live on the other drive.