Attiny85 not recognized at windows startup
I don't have enough reputations to make a comment so I will drop my 2 cents here.

There should be more elegant way to do this but as a fast solution I would recommend two things:


If it is possible, add a push button to your board to reset the MCU manually when the PC is booted up.
You can make a software reset after powering up the board by a certain time (e.g. 10 sec) by using watchdog timer.