I have Nokia Lumia 620 and installed the windows insider and it wont download any updates via internet. So I thought roll back to windows 8.1

The problem is it needs to download 1.5 gb and I have 512 kbps internet.

So I used fiddler and downloaded the 1.5gb file using download manager. It's some "signed.ffu" file.

Now the problem how to use that ffu file to install in windows phone.?

1 Answer 1


Below is the location of my file as created by the Windows Device Recovery Tool.


rm-821 is the phone model I have (930) so if you put your FFU in the equivilent directory the tool should pick it up

  • Ok I found many files in the directory. Shall I replace the RM846_3058.50000.1425.0001_RETAIL_im_india_233_01_450672_prd_signed.ffu.tmp with RM846_3058.50000.1425.0001_RETAIL_im_india_233_01_450672_prd_signed.ffu or shall I remove all the files and put RM846_3058.50000.1425.0001_RETAIL_im_india_233_01_450672_prd_signed.ffu..?
    – Ajit Hegde
    Nov 11, 2015 at 15:46
  • Just the file you manually downloaded. Ideally they should be called the same thing
    – ECiurleo
    Nov 12, 2015 at 6:20

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