Plug the installation disc or recovery disk into your computer. If you don't have one, you can create system repair disc or recovery disk on a working computer. That's to say, you need the Windows installation disc to boot your computer. If your boot sector or MBR runs into problems, you cannot start Windows normally. How to Run Startup Repair from installation disc Then it will scan the partition table, determine the active partition, load a copy of the boot sector into the PC's RAM, and hand off the startup process. When a PC starts, the BIOS will load the master boot code into the PC's RAM. How do the boot sector and MBR boot a computer? It also hosts the Master Boot Record (MBR), which contains the disk signature, partition table for the disk, and a small bit of code called the master boot code. The boot sector is a small section at the beginning of a hard drive, created when you format the hard drive, which contains some code and data that helps BIOS hand off the startup process to Windows. What are the boot sector and master boot record exactly? If not, you need to use command prompt for Windows 7 boot repair. If you backup MBR in advance, you can easily restore your computer and make it work as normal. And you will receive an error message like the following before Windows actually begins to load.įATAL: No bootable medium found! System halted. If you have Windows 7 boot problems, the boot sector or master boot record on your system partition may be damaged, corrupted, or has missing files.

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