Microsoft Windows Imaging Format file (.wim)
.wim file signature | application/octet-stream
The Microsoft Windows Imaging Format (WIM) is a disk image file format developed and maintained by Microsoft for capturing and deploying Windows system images. It is used in Windows installation media, system recovery tools, and enterprise deployment workflows to store one or more compressed images of files, folders, or entire installations. The format is considered safe to store or inspect, though mounting or restoring images from untrusted sources should still be done with standard file verification practices.
Magic Bytes
Offset 0
4D 53 57 49 4D 00 00 00
Sources: Wikipedia
All Known Signatures
3 signature variants are documented for .wim files across multiple sources.
| Hex Signature | Offset | Sources |
|---|---|---|
| 4D 53 57 49 4D 00 00 00 | 0 | Wikipedia |
| D0 00 00 00 00 | 0 | Wikipedia |
| 4D 53 57 49 4D | 0 | Gary Kessler |
Extension
.wim
MIME Type
application/octet-stream
Byte Offset
0
Risk Level
Safe
Validation Code
How to validate .wim files in Python
def is_wim(file_path: str) -> bool:
"""Check if file is a valid WIM by magic bytes."""
signature = bytes([0x4D, 0x53, 0x57, 0x49, 0x4D, 0x00, 0x00, 0x00])
with open(file_path, "rb") as f:
return f.read(8) == signatureHow to validate .wim files in Node.js
function isWIM(buffer: Buffer): boolean {
const signature = Buffer.from([0x4D, 0x53, 0x57, 0x49, 0x4D, 0x00, 0x00, 0x00]);
return buffer.subarray(0, 8).equals(signature);
}How to validate .wim files in Go
func IsWIM(data []byte) bool {
signature := []byte{0x4D, 0x53, 0x57, 0x49, 0x4D, 0x00, 0x00, 0x00}
if len(data) < 8 {
return false
}
return bytes.Equal(data[:8], signature)
}API Endpoint
/api/v1/wim
curl https://filesignature.org/api/v1/wim
See the full API documentation for all endpoints and parameters.
Related Formats
Frequently Asked Questions
What is a .wim file?
A .wim file is a Microsoft Windows Imaging Format file file. The Microsoft Windows Imaging Format (WIM) is a disk image file format developed and maintained by Microsoft for capturing and deploying Windows system images. It is used in Windows installation media, system recovery tools, and enterprise deployment workflows to store one or more compressed images of files, folders, or entire installations. The format is considered safe to store or inspect, though mounting or restoring images from untrusted sources should still be done with standard file verification practices.
What are the magic bytes for .wim files?
The magic bytes for Microsoft Windows Imaging Format file files are 4D 53 57 49 4D 00 00 00 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.
How do I validate a .wim file?
To validate a .wim file, read the first bytes of the file and compare them against the known magic bytes (4D 53 57 49 4D 00 00 00) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.
What is the MIME type for .wim files?
There is no officially registered MIME type for .wim files. Systems typically use application/octet-stream as a generic fallback when handling this format.
Is it safe to open .wim files?
Microsoft Windows Imaging Format file (.wim) files are generally safe to open. They are classified as low risk because they primarily contain data rather than executable code. However, always ensure files come from a trusted source.