Blue screen / stop code
Blue screen: SYSTEM_SERVICE_EXCEPTION
Windows stopped because a system service or driver hit an exception. Causes range from a bad driver to failing RAM, not one fix.
What this error means
A blue screen (unexpected restart with a sad-face or QR code) means Windows chose to stop rather than keep running in an unsafe state. SYSTEM_SERVICE_EXCEPTION means a core service or driver crashed. The stop code is a category, not a diagnosis of one brand of hardware.
Common causes
- A recently installed driver (graphics, storage, antivirus filter)
- Windows Update that included a driver
- Faulty RAM or a failing disk
- Incompatible software that installs a kernel driver
Safe fixes
After it boots again
- Unplug new USB devices and see if the crashes stop.
- Uninstall the newest app that installed a driver (VPN, "booster," extra antivirus) via Settings → Apps.
- Check Windows Update and also Optional updates only if you know you need a specific driver from your PC maker.
Boot into Safe Mode if it keeps crashing
Safe Mode loads fewer drivers. If the PC is stable there, a driver or startup program is a suspect. Use Settings → Recovery → Advanced startup if you can still open Windows, or interrupt boot three times only if you know you are getting to Windows Recovery, repeated hard power-offs can risk disk data.
Advanced fixes
Note the driver name if Windows shows one
Sometimes a file like nvlddmkm.sys or a storage driver is named. Search that name plus your PC model on the maker's support site. Install their driver, not a pack from a "driver updater" ad.
Memory diagnostic
Search Windows for "Windows Memory Diagnostic" and schedule it. It takes time and will restart the PC. A failure means RAM (or rarely the board) needs a technician, not a registry tweak.
When hardware may be involved
Crashes that happen in Safe Mode, during memory tests, or while the disk is making noises point to hardware. Back up files while the PC still boots.
When to get professional help
Recurring blue screens after driver rollbacks need a shop or the PC maker's support, with the stop code and the approximate time it started (new RAM, new SSD, new GPU).