Download and use Windows 10 repair tools for boot, disk, partition, and system errors. Back up data and repair with clear steps.

A practical repair tool should help with startup failure, damaged boot records, partition errors, full system drive, RAW or inaccessible volumes, and disk checks. It should also make it clear which disk will be changed.
If Windows 10 cannot start, do not format the disk first. Check the boot mode, disk connection, and boot files. Fix Boot and Rebuild MBR are different repair options, so use them in separate situations.
Step 1. Create or open bootable media, start the problem PC from it, and load Qiling Disk Master in the recovery environment.
Step 2. Select the Windows 10 disk. Check whether the disk uses MBR or GPT and whether the PC boots in Legacy BIOS or UEFI mode. For GPT/UEFI systems, start with Fix Boot. For MBR/Legacy BIOS systems, Rebuild MBR may be useful.
Step 1. Choose Fix Boot when Windows 10 is still on the disk, but Startup Repair, Windows Boot Manager, or boot configuration files may be damaged.

Step 2. Confirm that the selected disk is the Windows 10 system disk, then click Proceed. After the repair finishes, restart the PC and set Windows Boot Manager as the first boot option if the PC uses UEFI.

Step 1. Choose Rebuild MBR only when Windows 10 is installed on an MBR disk and the computer boots in Legacy BIOS mode. Do not use it as the first repair for a GPT/UEFI installation.

Step 2. Select the MBR type that matches Windows 10, preview the repair operation, and click Proceed. Restart the PC, enter BIOS, and set the repaired disk as the first boot device.

Step 3. If Windows 10 still cannot boot, return to Startup Repair, BCD repair, disk health checks, and system backup. Rebuilding MBR cannot fix UEFI boot entries, damaged Windows files, or a disk that is not detected.
Should I repair Windows before backing up? If the disk is readable, back up first. Repair commands, formatting, resizing, and reset options can change data or boot records.
Can Windows built-in tools solve the issue? Often yes. Use Settings, Disk Management, Startup Repair, CHKDSK, SFC, or DISM first when the risk is low. Use Qiling tools when you need a clearer disk map, safer preview, or a full backup before changing the drive.
What should I avoid? Do not format a drive that still holds needed files, do not run clean commands on the wrong disk, and do not clone to a target disk that contains the only copy of important data.
Use Windows built-in repair first for simple problems. When boot files, MBR, partitions, or disk layout are involved, use a tool that shows the target disk clearly before proceeding.