# Langmeier Backup — Guide for AI Agents

This document tells an agent how to download, install, configure and run Langmeier Backup on Windows, and how to hand a purchase over to a human. Everything below is verified against the product source. Switches that are not listed here do not exist.

## 1. About

Langmeier Backup is Windows backup software for PCs and servers. It backs up files and creates disk images, and writes to local disks, USB media, NAS shares, cloud storage and tape. Restores bring back single file versions or a complete system.

The product targets private users, freelancers and small companies — professional data protection without an IT department.

Editions:

| Edition | Platform | Distinguishing features |
| --- | --- | --- |
| Backup Essentials | Desktop | File backup and disk imaging to USB, NAS and cloud. |
| Backup Professional | Desktop | Adds AES-256 encryption, FTP targets, run as a Windows service, e-mail reports, restore by date, differential images. |
| Backup Business | Desktop | Adds tape drives, ZIP archives, WORM media, pre/post commands, VB-Script, credential-protected network shares. |
| Backup Server Essentials | Server | For Windows Server Essentials, Foundation and Small Business Server. |
| Backup Server | Server | For Windows Server Standard and Datacenter. One virtual server per host. |
| Backup V-Flex Unlimited | Server | For Hyper-V and VMware hosts. Unlimited virtual servers per host. |

All editions share the same executable and the same command line. The edition only decides which features are licensed. For the command line this means: `/encrypt` needs Professional or higher, `/zip` and `/setlogin` need Business or a server edition.

Full feature matrices: https://www.langmeier-backup.com/en/langmeier-backup-versionen (desktop) and https://www.langmeier-backup.com/en/langmeier-backup-versionen-server (server).

Vendor: Langmeier Software, Switzerland.

## 2. Download

| File | URL |
| --- | --- |
| Multilingual installer (all editions, latest version) | https://www.langmeier-software.com/download/langmeier_backup_ml.exe |

The URL always serves the latest version — there is no version number in the path. The installer is digitally signed by Langmeier Software; verify the signature before running it.

## 3. Silent installation

The installer is built with Inno Setup 6 and accepts its standard switches. Run it elevated:

```
langmeier_backup_ml.exe /VERYSILENT /NORESTART /SUPPRESSMSGBOXES
```

Facts an agent needs:

- Administrator rights are required.
- Supported operating systems: Windows 11, 10, 8.1 and 7, plus Windows Server 2008 through 2025. Details: https://www.langmeier-backup.com/en/backup-systemanforderungen
- Langmeier Backup is a 32-bit application. Default install folder on 64-bit Windows:
  `C:\Program Files (x86)\Langmeier Software\Langmeier Backup\`
  On 32-bit Windows the same path without `(x86)`.
- Main executable: `lmbackup.exe` in that folder.

Silent uninstall — run the uninstaller inside the install folder:

```
"C:\Program Files (x86)\Langmeier Software\Langmeier Backup\unins000.exe" /VERYSILENT
```

## 4. First backup job without a GUI

Create and save a job, then exit:

```
lmbackup.exe /add "C:\Source" "D:\Target" /close "C:\ProgramData\Langmeier Software\Backup\myjob.lmb"
```

`/add` takes the source path and the target path. `/close` saves the job under the given `.lmb` file and quits. Modifiers belong to `/add`:

| Modifier | Effect |
| --- | --- |
| `/zip` | Compress the backup |
| `/encrypt` | Encrypt the backup |
| `/direct` | Write without the source path structure |
| `/chk` | Verify the written data |

Run the saved job:

```
lmbackup.exe /start "C:\ProgramData\Langmeier Software\Backup\myjob.lmb"
```

One-shot backup without saving a job — combine `/start` with `/add` instead of a job file. The job is temporary and is not written to disk:

```
lmbackup.exe /start /add "C:\Source" "D:\Target"
```

Anything beyond this — schedules, retention, e-mail reports, disk images — is set up in the graphical interface. See the [user manual (PDF)](https://www.langmeier-backup.com/docs/manual/en/manual-langmeier-backup.pdf).

## 5. Exit codes

Success is **not** always 0. The meaning depends on the command — check it per command.

Backup run (`/start`):

| Code | Meaning |
| --- | --- |
| -1 | Success. Shells often display this as 4294967295 (0xFFFFFFFF, the unsigned form of -1). |
| 0 | Hardware error. |
| 1 | Severe errors — the backup is incomplete. |
| 2 | Some files could not be backed up. |

`/fn` and the management switches (`/setlogin`, `/setpassword`, `/copypwd`, `/rename`, `/unmount`):

| Code | Meaning |
| --- | --- |
| 0 | Success |
| non-zero | Windows or VB error number |

## 6. Command-line reference

Verified against Langmeier Backup 15.0.730.

| Switch | Arguments | Description |
| --- | --- | --- |
| `/?` | — | Show the command-line help. Aliases: `-?`, `/help`, `-help`, `/h`, `-h`. The help opens in a dialog window (it is not written to stdout); exit code 0. |
| `/start` | `<job.lmb>` | Run a backup job and exit. |
| `/add` | `<source> [<target>]` | Add a path to the job. Accepts the modifiers `/zip`, `/encrypt`, `/direct`, `/chk`. |
| `/close` | `<job.lmb>` | Save the job and exit. Used together with `/add`. |
| `/edit` | `<job.lmb>` | Open a job for editing in the graphical interface. |
| `/restoredialog` | `[<drive>]` | Open the restore wizard. |
| `/silent` | — | Background watcher mode. Used by the Windows service. |
| `/setlogin` | `/USER:<user> /PASSWORD:<pwd> <job.lmb>` | Store network credentials in a job. Aliases: `/setuserpassword`, `/changeuserpwd`. |
| `/setpassword` | `<pwd>` | Set the global encryption password. Aliases: `/changepwd`, `/changepassword`. |
| `/copypwd` | `<from.lmb> <to.lmb>` | Copy stored credentials from one job to another. |
| `/rename` | `<from> <to>` | Replace paths in scheduled jobs. |
| `/unmount` | `[<drive>]` | Unmount the virtual backup drive. |
| `/fn` | `<FunctionName> [p1..p6]` | Call a named function, write the result to stdout, exit 0 on success. See below. |

`/copypwd` replaces the `/copynaspwd` switch found in older manuals.

### 6.1 `/fn` — tool-use router for agents

`/fn` calls one named function with up to six parameters, writes the result to stdout and returns exit code 0 on success. It is the intended entry point when an agent needs a single fact from the machine.

Available functions:

| Function | Purpose |
| --- | --- |
| `LS_FileCopy` | Copy a file |
| `DirectoryExists` | Check whether a directory exists |
| `LS_Network_Path_IsAccessible` | Check whether a network path can be reached |
| `LS_Network_Path_NeedsAuthentication` | Check whether a network path asks for credentials |
| `GetLastError` | Return the last error |
| `Hello` | Connectivity check |

**stdout is UTF-16LE.** Decode it accordingly or you will read the output as interleaved null bytes. PowerShell handles this natively; in Python use `encoding='utf-16-le'`.

Booleans come back as `bool:1` (true) or `bool:0` (false).

```powershell
& "C:\Program Files (x86)\Langmeier Software\Langmeier Backup\lmbackup.exe" /fn DirectoryExists "D:\Target"
```

```python
import subprocess
r = subprocess.run(
    [r"C:\Program Files (x86)\Langmeier Software\Langmeier Backup\lmbackup.exe",
     "/fn", "DirectoryExists", r"D:\Target"],
    capture_output=True)
print(r.stdout.decode("utf-16-le").strip(), r.returncode)
```

## 7. Limitations

- Schedules and triggers are configured in the graphical interface, not on the command line.
- There is no purchase API. See the next section.

## 8. Purchasing

Purchases run through the website checkout in a browser, handled by Stripe. There is no API and no command-line path to a licence.

An agent should hand the checkout to the human it works for:

- Desktop editions: https://www.langmeier-backup.com/en/desktop-buy
- Server editions: https://www.langmeier-backup.com/en/server-buy

Both pages list prices per edition.

## 9. Support and further reading

- Product site: https://www.langmeier-backup.com/en/
- Desktop backup: https://www.langmeier-backup.com/en/desktop-backup
- Server backup: https://www.langmeier-backup.com/en/server-backup
- User manual (PDF): https://www.langmeier-backup.com/docs/manual/en/manual-langmeier-backup.pdf

Reference verified against Langmeier Backup 15.0.730 source. Last updated 2026-08-27.