Installing USBasp drivers and software
https://www.fischl.de/usbasp/
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Getting a proper working driver using Zadig
you can read proper instructions here
https://sparks.gogo.co.nz/usbasp_drivers.html
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How to flash using CMD
open cmd in the folder the .hex files are
then use the command string with proper fuses
Tiny 85
or use the full file directory
Tiny 25
How to flash using Atmel studio adding an external tool added as a button in the main menu header
http://www.ledoelectronics.com/Productos/AVR/usbasp_s7.pdf
for Tiny25 and 85 you need 2 different commands