How to Fix BSOD BAD_SYSTEM_CONFIG_INFO (0x74)

By ErrorFix · Updated October 20, 2026 · 9 min read

What error 0x74 means

Every time Windows starts, it first reads its own instruction manual: the Boot Configuration Data (BCD) that tells it which operating system to load and how, plus the registry hives (SYSTEM, SOFTWARE, SECURITY, SAM, DEFAULT) that hold the system's core settings. BAD_SYSTEM_CONFIG_INFO — stop code 0x00000074, usually shortened to 0x74 — means Windows opened those files and found them corrupted, so it stopped with a blue screen rather than boot into an unknown state.

This error most often shows up right after a Windows update, a forced shutdown, a power cut, or a disk that is starting to fail — anything that can interrupt Windows while it is writing to the BCD or the registry. Because the damage is in files on the disk rather than in a dead component, the fix is a data repair job: rebuild the boot data, restore the registry from the automatic backup Windows keeps, and repair the disk itself. Work through the steps below in order. None of the first six steps touch your personal files, so you are not risking your data by trying them.

Common causes

• Corrupted Boot Configuration Data: the BCD file that lists your Windows installation can get damaged by an interrupted update or a forced shutdown, and without it Windows does not know how to boot.
• Damaged registry hives: the SYSTEM, SOFTWARE, and other core registry files can be corrupted by a bad write, a crash during an update, or disk errors — the literal bad system config info this error names.
• Disk errors or bad sectors: a drive with failing sectors corrupts whatever files sit on them, and boot data and registry files are read on every single startup, so they are prime targets.
• Interrupted Windows updates: updates rewrite boot data and registry entries; a power cut or forced restart mid-update leaves them half-written and unusable.
• Faulty RAM: bad memory silently corrupts data as Windows writes it, so the same configuration files can get corrupted again and again until the defective stick is replaced.

How to fix error 0x74 — step by step

Work through these fixes in order. Your PC will not boot normally during this, so everything runs from the Windows Recovery Environment.

1. Boot into the Windows Recovery Environment. Turn the PC on and, while the Windows logo shows, hold the power button until it shuts off. Repeat this three times — on the third boot Windows gives up on normal startup and opens Automatic Repair. Click Advanced options, then Troubleshoot, then Advanced options again, then Command Prompt. You may need to select your account and enter its password. One important note: in this environment your Windows drive may not be C — it often shows up as D or E. Type bcdedit | find "osdevice" to check which letter your installation uses, and use that letter in the commands below.
2. Run Startup Repair from the recovery menu. Before running commands by hand, let Windows try to fix itself. Go back to Troubleshoot > Advanced options and choose Startup Repair, then select your Windows installation when asked. It scans the boot configuration and core system files and repairs what it finds. Give it a few minutes. This resolves a fair number of 0x74 cases by itself, especially ones left behind by a bad update. If it reports that it couldn't repair your PC, continue — the manual BCD rebuild below is the heavier fix this error usually needs.
3. Rebuild the BCD with bootrec commands. Open Command Prompt from the recovery Advanced options and run the boot repair sequence one line at a time. First, bootrec /fixmbr and then bootrec /fixboot to repair the master boot record and the boot sector. Next, protect yourself: back up the current boot data with bcdedit /export C:\BCD_Backup (adjust the drive letter if needed). Then strip the old BCD file of its protection with attrib c:\boot\bcd -h -r -s and rename it out of the way with ren c:\boot\bcd bcd.old. Finally, run bootrec /rebuildbcd — it scans the drive for Windows installations and builds a brand-new BCD. When it asks whether to add the installation to the boot list, type Y and press Enter. Close Command Prompt and restart. If Windows boots, you are done.
4. Restore the registry hives from the RegBack backup. If 0x74 survives the BCD rebuild, the registry hives themselves are the problem — and Windows keeps an automatic backup you can restore. Back in the recovery Command Prompt, check the backup first: run dir C:\Windows\System32\config\RegBack. If the files listed there show real sizes (not zero bytes), the backup is usable. Back up the current hives with md C:\RegBackup then copy C:\Windows\System32\config\* C:\RegBackup. Then restore the backup over the live registry with copy C:\Windows\System32\config\RegBack\* C:\Windows\System32\config\, confirming each overwrite. This replaces the SYSTEM, SOFTWARE, SECURITY, SAM, and DEFAULT hives with their last working versions. Restart and test.
5. Run CHKDSK and SFC to repair the disk and system files. If corruption keeps coming back, the drive itself is likely the source. From the recovery Command Prompt, run chkdsk C: /f /r with the correct drive letter. The /f flag fixes file-system errors and /r finds bad sectors and recovers readable information — expect this to take an hour or more on large drives. When it finishes, repair the protected system files from outside Windows with sfc /scannow /offbootdir=C:\ /offwindir=C:\Windows\. If SFC reports corruption it could not fix, run DISM /Image:C:\ /Cleanup-Image /RestoreHealth to repair the component store, then run SFC once more.
6. Test your RAM for hardware faults. Software repairs are pointless if bad memory keeps mangling the files they restore. From the recovery Advanced options, choose Startup Settings, restart, and run the Windows Memory Diagnostic — or press Win + R on any machine and type mdsched.exe for the same tool. Let the full test complete. Any reported error means a memory stick is defective and must be replaced before the repairs in the previous steps can hold. If you have two sticks, test them one at a time to find the bad one.
7. Reset Windows or reinstall as a last resort. If the BCD rebuild, registry restore, disk repair, and memory test all fail, the damage is beyond file-level repair. Go back to Troubleshoot and choose Reset this PC, then Keep my files — this reinstalls Windows while preserving your personal files, though you will need to reinstall your programs afterward. If even the reset fails, create Windows installation media on another computer, boot from the USB drive, and perform a clean install. A clean install clears BAD_SYSTEM_CONFIG_INFO in every case because it writes entirely fresh boot data and registry hives.

Did this fix it? Quick checklist

• BCD rebuilt with bootrec /rebuildbcd and PC boots normally
• Registry hives restored from RegBack or confirmed healthy
• CHKDSK and SFC completed with no unrepairable errors
• Memory diagnostic passed and the PC survives two consecutive restarts

If 0x74 keeps returning after every repair, check the drive's health numbers with the manufacturer's tool or CrystalDiskInfo — a drive reporting reallocated or pending sectors will keep corrupting files no matter how many times you repair them, and it needs replacing. Also confirm the RAM test passed on every stick; a single bad stick explains corruption that reappears days after a successful repair. And double-check that you are running the commands against the correct drive letter in the recovery environment — repairs run against the wrong volume silently do nothing.