I installed Windows XP on the C drive, and then installed Windows 7 on the D drive. This is all normal, because I originally backed up the XP system, so I used a key to restore the C drive to restore, but the problem will come out, in the system startup items, only Windows XP and one-click restore two options There is no way to enter the Windows 7 system, because I have not been exposed to Windows Vista, directly from XP to Windows 7, so I don't know much about its startup principle, so I studied the problem in one afternoon, and I also learned about Windows by the way. 7 system startup principle.
Before solving the problem, let's first understand how the startup principle of Windows XP and Windows 7 is different. How to start the dual system:
In Windows 7+XP dual system, Windows 7 uses bootmgr to take over the system. mode. After the computer self-test is complete, start looking for the active primary partition (generally C:) and load it.
There will continue to read the boot configuration file (ie C:BOOTBCD) and c:boot.ini under the active partition, and list the boot menu according to the boot information stored by BCD and Boot.ini (that is, the dual system boot menu). . For dual system users, it is usually listed "Microsoft Windows 7" and "old versions of Windows".
If you choose the former, Bootmgr will give control to Winload.exe under Windows 7 system directory (under Windowssystems) and then start Windows 7. Select the latter, Bootmgr will give control to NTLDR, then start reading c:boot.ini and list the boot menu configured in it.
The startup failure mainly occurs in Bootmgr (if the file is lost), BCD (boot information configuration error), Winload.exe (the file is lost and Vista cannot be started), Ntldr (the file is lost and XP cannot be started) on. (My situation belongs to the bootmgr file is missing, BCD file startup information configuration error)
Let's solve the problem below:
1, first we need several backup files (bootmgr, ntldt, bcd, bootsect), if you have Windows 7 system disk or image can be extracted directly from it.
There is also a tool ——EasyBCD
Note: The operation of EasyBCD under XP requires Microsoft .NET Framework 2.0 support.
2, the following operations are carried out in Windows XP, because hidden files and system files, so it is best to display the system and hidden files, click on the folder options to view, remove hidden protected system files (recommended) And choose to choose to display the files and folders.
Copymgmg, ntldt (usually under the C drive, do not copy) to the C drive. (This C drive is the default system, depending on the situation)
Copy bcd, bootsect to the C:boot directory
3, then run EasyBCD
switch to the left side“ ADD/Remove Entries”, select the original invalid boot menu in the right pane, click Delete Delete, and then add the startup item under Add An Entry. Add XP to start in Version select "Windows NT/200/XP", Drive select C:, Name to Windows XP (Figure 3). Same as above, add the startup item of Windows 7 (Version selects Windows Vista/longhom, Drive selects D:, Name is set to Windows 7), and clicks ADD Entry to save the configuration when finished.
4, then open “ Run & rdquo; (Start > Run), enter cmd
Enter C:boot directory and enter "lds;bootsect /nt60 C:” (delete is nt52, without double quotes) < Br>