Try this method to fix the window 10 startup error after resetting:
Removing secondary GPU and external HDDs or SSDs
External HDDs or SSDs, as well as a secondary GPU, are being removed.
Other customers have stated that disconnecting all superfluous gadgets helped them get rid of the problem code 0xc0000221 completely. It's very conceivable that this problem is caused by your power supply's inability to support all connected devices.
Let's see if this notion holds true by disconnecting all non-critical peripherals and secondary HDDs, external HDDs, DVD optical drives, second GPU from SLI (or CrossFire arrangement).
After your computer has been stripped down to its base essentials, turn it on and check whether it can get through the startup screen. If your computer boots up without the error number 0xc0000221, reconnect the non-essential components one by one until you find the source of the problem.
