First principle for repair of a BSOD (very rare these days) is to do NOTHING.
Turn it off, unplug it, have a cup of tea, walk the dog or something.
Chances are that it will not recur.
The vast majority of total Windows OS stuffups are from well meaning attempts to tinker with the
OS and or the Registry.
jimjim1's advice is good and will fix many problems.
DO NOT download or use any "We will fix yr PC" programs 'cos they won't.
A recent and tested tested disk image is your best friend (I prefer Macrium)
Problems persist? Just restore the latest image.
A 4GB drive will hold a lot of compressed images and cheap at the price.
Mac