Kindly I ask your attention.
Could you be so kind and edit your question with additional information like:
Android version ???????
Viper ????? is a program or a website?
And/or,
Start your browser and search for:
https
/www.google.nl/search?output=search&sclient=psy-ab&q=How+to+set+download+folder+SD+Card+in+Android%3F&btnK=
When Viper is an app:
How to set download folder SD-Card in Viper?
How to download from Viper to SD-Card?
Or simular to it.
Hopefully I let you known enough, that you will find the answers you seek!
Good luck and have fun doing it!
Best Regards,
MeneerWitte