To solve the dual-system problem, first install win7 and then install ubuntu. We found that ubuntu could not identify the installed win7 and only saw the problem of a whole hard disk.

To solve the dual-system problem, first install win7 and then install ubuntu. We found that ubuntu could not identify the installed win7 and only saw the problem of a whole hard disk.

To solve the problem of ubuntu 64-bit dual system, first install win7 and then install ubuntu. We found that ubuntu could not identify and detect installed win7, and only one full hard disk could be seen, you cannot see that the win7 partition has been completed.

I don't know the cause of this problem, but you can solve it as follows.

1. First download an ubuntu ISO, and then implement it into a USB flash drive through UltraISO to form a boot disk and an installation disk.

2. Start the USB flash drive and enter the system interface. Select try ubuntu.

3. Enter "sudo dd if =/dev/zero of =/dev/sda bs = 1 count = 8 seek = 512" in the shell.

4. Go to the ubuntu installation page through the wizard again, and you will be able to see the relevant partitions. Then you can install them.