TL;DR: Format the Windows path the way docker expects: forward slashes and lowercase drive, like `-v c:/data URIs/data`, or quote the path. Backslashes and unquoted drive letters break the volume parser. On Docker Desktop for Windows, `-v C:\data URIs/data` fails while `-v c:/data URIs/data` works.

## The error

```text
docker: Error response from daemon: invalid volume specification: 'C:\data URIs/data URIsrw': invalid volume specification.
```

## Fix it

1. Rewrite the bind with forward slashes:
   `docker run -v c:/data URIs/data [image]`
   Expected: container starts.
2. In PowerShell, quote to stop the shell mangling the path:
   `docker run -v "c:/data URIs/data" [image]`
   Expected: works.
3. From Git Bash/MSYS, use the posix-style path or double slashes:
   `docker run -v //c/data URIs/data [image]`
   Expected: works.

## When this applies
- Docker Desktop on Windows with -v or --mount bind paths
- CI on windows-latest runners

## When this does NOT apply
- Linux hosts (bind paths are native there)
- "includes invalid characters for a local volume name" (named volume rule, separate skill)

## Versions
Docker Desktop 4.x on Windows.

## Why it happens
The volume spec parser splits on `:` and treats backslashes as escapes. `C:\data` parses into something the validator rejects, while `c:/data` splits cleanly into source and destination.

## Edge cases
- File sharing must be enabled for the drive in Docker Desktop Settings > Resources > File Sharing, or the bind silently shows an empty dir.
- WSL2 backend: prefer paths inside the WSL distro (`[HOME]/...`) over /mnt/c; they are much faster.
- `--mount type=bind,source=c:/data,target=/data` is stricter but gives clearer errors than -v.