sahil92 said:
@davidhk :thnx a lot
before some day i tried your 2nd option : "http://www.microsoft.com/en-us/software-download/techbench"
from this link i downloaded other ISO file having version of my installed OS.
i successfully updated OS from that ISO.
so then my update issue is solved automatically..
thnx again..
:)
You are welcome.

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