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Error: C:\Users\Raini>bitcoin-qt.exe is not a reliable application.
I think you just forgot to point command prompt to the correct directory before executing the command.
cmd should be working in "
C:\Program Files\Bitcoin" if you're using the default installation directory.
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C:\Users\Raini>bitcoin-qt.exe -dir=E:\Bitcoin -reindex
You should start cmd in the directory where bitcoin-qt is located or change the working directory using "
cd" command.
eg.:
cd C:\Program Files\Bitcoin
Then enter the command vv181 instructed you to use.