After Windows 7 and Ubuntu are installed, the Ubuntu boot file is accidentally deleted and an error occurs: Unknown filesystem; grub rescue>.

A long time ago, the ubuntu12.04 system was installed on Windows 7 7 using hard disk installation. A 10 Gb hard drive partition F is used to store the boot file of ubuntu12.04. In fact, you can create a boot disk of ubuntu12.04. My partition has a total of GB space. The layout is as follows: C disk stores win7 system files, including programs, 40 GB in total; D disk and storage data, 80 GB; e disk 70 GB, data storage; 10 Gb F disk, used to store the boot file of ubuntu12.04; C ~ The F partition is in the standard NTFS format. The other 50 GB partition is formatted to convert the original NTFS format to the FAT32 format for installing ubuntu12.04.

To be honest, I am quite familiar with ubuntu12.04 installation. I used a USB flash drive to install Ubuntu with a single system. I used grub4dos. I used a hard disk to install win7 and Ubuntu dual systems. I used a USB flash drive to install Windows 7 and Ubuntu dual systems, use ultraiso; Use Virtual Machine Tools VMware and virualbox in Windows XP to install ubuntu12.04.

Recently, I think Windows 7 has installed a large push software, which is too slow. Therefore, I have merged drive F and drive E. I want to reinstall Windows 7, so I formatted the Ubuntu Installation File. However, when you reinstall Windows 7, the following information is displayed:

Error: unknow filesystem
Grub rescue>
How can I solve this problem after multiple restarts?

Related methods are found online.

Here is a similar blog: solution: XP and Ubuntu dual-system, directly deleting Ubuntu causes XP to fail to be guided, error: Unknown filesystem, grub rescue, similar to my problem, I only use Windows 7 and Ubuntu dual systems, but I only use Windows XP and Ubuntu dual systems. The method is simpler and more feasible. It is to use PE to repair the MBR primary sector.

My solution is:

Find another computer, prepare a 4g usb flash drive, download the IOS image of the win7 operating system, and create a USB flash drive. (No way. If your computer cannot be started, you have to seek help from another computer !)

Go back to your computer, set the first boot item in BIOS to USB, display my computer as removeable device, and finally plug the prepared USB flash disk into your computer.

1. Use the ultraiso software to create the win7 boot disk.

The win7 version I downloaded is a cn_windows_7_ultimate_x86_dvd_x15-65907.iso file. You can download win7 system images from here: Windows 7 Chinese/English flagship edition (32/64 bits) official msdn version of the disc image download

Originally wanted to use Microsoft to provide Windows7-USB-DVD-Download-Tool-Installer-en-US software to make win7 U disk boot disk, did not expect to enter the last BIOS will be set to the first boot items, did not want to guide the success, so I tried to use ultraiso.

This document is provided by my Baidu Library: How to Create a USB flash drive to install the win7 system. As a result, the win7 USB flash drive is successfully created.

2. Enter the bios, set the USB flash drive as the first boot item, and save it.

My Asus laptop is set to enter BIOS by pressing F2. The keys for entering BIOS for different brands or series of the same brand are different, generally, you can check the corresponding BIOS buttons Online Based on your computer model.

In addition, there is a prompt for BIOS setting keys during boot.

3. After saving step 2 settings, insert the prepared USB flash drive and install the win7 system normally. If it succeeds, the win7 system will be successfully installed.

 

Cause: After Ubuntu is installed, the content in MBR is changed, pointing to grub of ubuntu. Grub has both win7 and Ubuntu boot, grub is also replaced when Ubuntu is formatted. The result is that the MBR cannot find the boot system and an error occurs. If you know the principle, there is a solution. Since the MBR has an error, you only need to restore the content in the MBR.