[General Questions and Answers] alecxs:
There are free programs like OSFMount or DiskInternals Linux Reader for mounting (android) linux file system images on Windows. Also 7-Zip for Windows can extract files from linux file system images.

However, there is metadata like user identifier and group ownership, file permissions, SELinux context (user role type range) stored for each file, which gets lost once you have saved linux files to windows disk. Without this metadata you can not restore files to phone.

Regardless you can extract files in windows if you just care about pictures, music files etc. Maybe one day there is a developer who may write such a program no matter its useless for restoring complete user data to phone.

Regarding the userdata*.backup files (no cwm) this is a chinese feature not provided by google android open source project. Without source code its nearly impossible to analyze the checksum algorithm. You can not re-create a userdata*.backup file.

What you can do is unpacking it. make a guess. cut off the first 512 byte header of each file which is probably the checksum. then merge the files together. Now you have a file for further analysis. Its probably either a ext4 disk image or a (gz compressed) tarball archive. a disk image can be mounted as a new drive, metadata keeps preserved in this case. a tarball archive must extracted with gnu tar to linux file system. when extracting with 7-Zip you will lose metadata.

There is a risk of tarball archive is unheadered Tar, in this case 7-zip will not extract it. If your phone is encrypted, the disk image is probably encrypted disk image (thats where the hacker stuff starts).

If you want to remove the checksum in windows, there is a small problem. There is no such command. You can use a third party command line utility Trunc to try it. (truncate deletes only from tail)

Another way for Windows, you can use some linux utils with cygwin. I don't know exactly how to do it, but [MENTION=4292543]Doc_cheilvenerdi.org[/MENTION] released a Windows script Odinatrix which converts unheadered Tar to Ustar Tar. From this you can use some linux utils (i don't know if it works for converting backups, too)

1. unpack the Odinatrix-WINDOWS.zip file. copy the folder named "files" containing cygwin linux utils. rename the folder to bash (or any meaningful name)

2. create a new folder on Windows Desktop

3. move the backup files to <some folder>

4. open the Windows Command Prompt

goto Windows Start - Run...

type: %SystemRoot%\system32\cmd.exe - press OK

now type the following commands in Windows terminal console:

5. add bash folder to windows environment variable %PATH%

(example: PATH=%PATH%;C:\Program Files\bash)

PATH=%PATH%;<path to bash folder>

6. change directory and list backup files

cd %UserProfile%\Desktop\<some folder>
dir /a userdata*.backup*

7. cut off 512 byte header from each file using (cygwin) gnu "dd" linux util like [MENTION=7128214]ektoric[/MENTION] suggest in post #6.

do this for each file, skipping 512 bytes only (without unpacking). replace the wildcard * with <date>_<time>

dd if=userdata*.backup of=userdata*.part0 bs=512 skip=1
dd if=userdata*.backup1 of=userdata*.part1 bs=512 skip=1
dd if=userdata*.backup2 of=userdata*.part2 bs=512 skip=1
dd if=userdata*.backup3 of=userdata*.part3 bs=512 skip=1

8. merge the files with windows

copy /v /y userdata*.part0 /b + userdata*.part1 /b + userdata*.part2 /b + userdata*.part3 /b userdata*.img /b

9. try to mount the userdata*.img with OSFMount. if not working, try extracting with 7-zip.

Besides this linux is no hacker-os and just as easily operated as windows. You can boot a live distribution from usb-stick without installing.

for further questions, please visit the main thread

[Q] How to Extract data from .Backup file ? - Created with android system recovery