The main advantage of Android operating system is that it is highly customizable. When you have a Android phone, there are number of possible things you can do. One of such things is installing custom ROMs. But custom ROMs are experimental things and you cannot have guarantee of smooth working before installing them. So we always suggest that you should take a full backup of your current ROM or firmware. Custom recoveries give you that facility of backup and restore so that you can restore it afterwards if anything goes wrong with the ROM which you are installing. You can read further on backup and restoring ROM in following article:
- How to Backup whole ROM/Firmware via Clockworkmod (CWM) recovery.
Once you have taken the backup of your regular ROM or firmware, then you are free to try all the experimental ROMs and mods. But if you don’t take enough while backing up or restoring the ROM, you can have unsuccessful restore. Here are possible reasons of unsuccessful restore.
- A bad or damaged backup
- Problem with kernels related to mounting & un-mounting /system,/data,/cache
- Renamed backups.
Here are some things required before you begin with the procedure.
- You will require a personal computer to edit the files.
- You will also require Notepad ++. Here is the link from which you can download it.
- You will require micro SD card reader to connect your memory card to your computer.
Once you have these things, you are set to go.
- First remove the memory card from your phone.
- Make sure you have installed Notepad++ on your computer.
- Connect your memory card to your phone via a memory card reader.
- In the list of files search for the folder named clockworkmod. Your backup is stored in that folder. Double click it to open that folder
- In that folder further you will see a folder named backup. Open that folder.
- The again you will see folder/s which will have date and time in their names. These are backups which you have taken. Now open the folder from which you want to make a restore.
- In that folder, you will find a file named nandroid.md5 as shown in the image below.
- Now right click on that file and click on the option edit with notepad++.
- In that file, you will find some text written. Now select all the text and delete it.
- After you delete the content in the .md5 file, click on the file option in the upper left corner and click on the save option. Image given below illustrates it.
- Now again put the memory card in the phone and try to restore the same backup. It should work.
That’s it. The content in the nandroid.md5 file caused the error. When Clockworkmod makes a nandroid backup, it checks against the numbers in the nandroid.md5 file. When numbers don’t match up, it causes the MD5 Mismatch error. By deleting the content in the file, you force it to skip this step. And if you have any doubt, make sure to ask it in comments and please hit like if it works for you.