Heres The List:
1] Check The Power Supply
When I was trying to program a PICAXE microcontroller it always used to show a error that unable to program I tried to solve this problem and then I finally came to know that my power supply was not appropriate. I was using a wall adapter at first when I replaced it programming started taking place smoothly. My programmer required external power supply
2] Selecting Correct Serial Port
In the programming software that you are using you need to specify the port to which you have connected your programmer to. I have failed to program my PIC microcontrollers because I didn't select the correct serial port.
3] Installing Drivers
Before being able to use your programmer you need to install the drivers necessary for the functioning of the programmer. When you connect the programmer for the first time it will automatically install them but if it doesn’t download it from the internet. While programming the arduino it did not automatically install the drivers I had to specify the locations of the drivers.
4] Pull Ups
Many microcontrollers require pull ups in their circuit before they can be programmed like the picaxe microcontroller requires 10k pull up resistor at the serial pin to get programmed otherwise it shows a error. Many other microcontrollers too require pull ups they might 1 or several.
5] The Programming Software Is Not Detecting The Microcontroller
This again is a problem with your power supply check your power supply again and again connect the programmer to the computer and now it should detect it but if it still doesn’t detect it there might be a problem in your programmer.