Using an USBtinyISP to program AVR microcontrollers.

Hello everyone,

I purchased an USBtinyISP v2.0 and installed a driver from "Adafruit", and when I want to program an ATtiny85, the Arduino IDE says :

avrdude: Error: Could not find USBtiny device (0x1781/0xc9f)

So can anyone help me please ?

I purchased an USBtinyISP v2.0 and installed a driver from "Adafruit", and when I want to program an ATtiny85, the Arduino IDE says : avrdude: Error: Could not find USBtiny device (0x1781/0xc9f)

Not without a schematic of how your ATtiny85 is wired to the device.
draw a schematic with pen and paper and take a photo of it with your cell phone and post it.
Also, do you know ANYTHING at all about SPI (YES or NO question) ?
If YES, what ?