Install on Windows (SmartScreen, antivirus)

KoboldCpp for Windows is a single .exe file. There is no installer.

Pick your file. Most NVIDIA users need koboldcpp.exe; see Download KoboldCpp for the others.
Your PC File
NVIDIA graphics card koboldcpp.exe
AMD, Intel or no graphics card koboldcpp-nocuda.exe
Older processor or older NVIDIA card koboldcpp-oldpc.exe
Put the file in a folder of its own, for example C:\mystuff. When you start it by double-clicking, models that KoboldCpp downloads for you are saved in this folder. Download Dir: on the Loaded Files tab changes that. Use a path with plain ASCII characters (no umlauts or other accented letters).
Double-click the file. A console window opens, then the launcher.
If Windows shows "Windows protected your PC", click More info, then Run anyway. This is expected: the file is not signed.

Your PC	File
NVIDIA graphics card	`koboldcpp.exe`
AMD, Intel or no graphics card	`koboldcpp-nocuda.exe`
Older processor or older NVIDIA card	`koboldcpp-oldpc.exe`

SmartScreen and antivirus warnings

KoboldCpp's exe files are not code-signed, and they unpack their libraries into a temporary folder when they start. Some antivirus programs flag this as suspicious. These are false positives, as long as the file came from the official GitHub releases. See Staying safe.

What you see	What to do
"Windows protected your PC" (SmartScreen)	Click More info, then Run anyway.
Microsoft Defender or another antivirus reports a trojan or "suspicious" file, or deletes it	Restore or re-download the file, add it to your antivirus exceptions, and report the false positive to your antivirus vendor.
The exe shrinks to 0 bytes, or "Failed to extract … decompression resulted in return code -3!"	The file is damaged, often by your antivirus. Download it again; if it happens again, add an exception.
Smart App Control blocks it	Smart App Control has no exception list. It blocks KoboldCpp for as long as it is turned on.

If the window closes straight away

When KoboldCpp crashes, the console window can close before you can read the error. Run it from Command Prompt instead, so the message stays on screen:

Press the Windows key, type cmd and press Enter.
Type cd followed by the folder with your file and press Enter. Then type your file's name and press Enter:
Command Prompt
```
cd C:\mystuff
koboldcpp.exe
```

KoboldCpp writes no log file by itself. Errors from the launcher appear in a message box.

Common causes:

Your processor lacks AVX2, or your NVIDIA card or driver is old. Errors like WinError 1114 or 0xc000001d often mean this. Use koboldcpp-oldpc.exe, or update your NVIDIA driver. See System requirements.
The console stays blank and the launcher never appears. KoboldCpp could not unpack itself. It needs about 1 GB of free space for temporary files on the system drive, and antivirus software can block the unpacking. Free up space, or try the smaller koboldcpp-nocuda.exe.
Antivirus removed part of the file. See the table above.

More: KoboldCpp won't start.

Using the command line

Pass flags after the file name. With a model, KoboldCpp skips the launcher and starts straight away:

C:\mystuff\koboldcpp.exe --model C:\models\mymodel.gguf --contextsize 8192

koboldcpp.exe --help lists all flags. They are also in the flag reference.
--config mysettings.kcpps starts with a saved configuration.
The launcher opens a browser after loading; on the command line, add --launch for the same.
The launcher is not accessible to screen readers. Screen reader users can run KoboldCpp entirely from the command line.

More: Command line.

Advanced: unpack for faster startup

The exe unpacks itself every time it starts. To skip that, unpack it once into an empty folder, then start koboldcpp-launcher.exe in that folder. It needs no Python installation.

koboldcpp.exe --unpack C:\kobold-unpacked

In the launcher, the same is on the Extra tab: Unpack KoboldCpp To Folder. The target folder must be empty.

Advanced: open files with KoboldCpp

On the Extra tab, Register makes KoboldCpp the program that opens .gguf, .ggml, .kcpps and .kcppt files for your user account. Unregister removes this. It only works with the standalone exe.

Advanced: Windows 7

Windows 7 is not recommended. The main builds use functions that only exist in Windows 8 and newer.

Use koboldcpp-oldpc.exe. Its libraries skip the Windows 8 functions.
If it still fails with an error about msvcp140.dll or GetSystemTimePreciseAsFileTime, one user fixed it by unpacking KoboldCpp and replacing the msvcp140.dll in the unpacked folder with an older version. Don't replace the one in Windows itself.
DLL load failed while importing pyexpat was fixed by installing the Windows update KB3063858.
The third-party VxKex compatibility layer can make the main builds run.
CUDA on Windows 7 is untested.