try to repair using windows installation media.
or try restoring to previous date in safe mode if possible
If possible, capture the BSOD and paste it here.
It will have more details, for the people to help.
This can happen when one of the driver's of a core system hardware mess up, which maybe due to a multitude of reasons. BCCode: 50 is usually associated with ram, graphics card, hard disk, and hardware components that require an active windows service. Since your system boots up, I suspect this is very less the effect of a hardware fault. (Try cleaning your ram slots, gpu fan etc)
Most of the time, it can also be triggered by a bad sector in your HDD as well. So booting into a prompt and doing chkdsk is recommended.
If it still triggers the error, it may be caused by a software. This can either be a system level configuration error or corruption of config data by another program (say, an antivirus suite). To resolve, boot into "Last known" or "Safe Mode", do a system restore to the previous day the error occurred.
Remove ram modules, clean them and the slots too. Remount them. Also check biso for any sort of abnormal cpu temp. Do test your pc using a linux live distro.
You could also try booting in safe mode and removing all installed drivers. Then boot normally into Windows and try reinstalling them.
Make sure you check your hardware as mentioned in the above posts!
You can use this utility to check for RAM issues:
Memtest86+ - Advanced Memory Diagnostic Tool
You'll need to use a bootable flash drive or CD.
