Reformat problem.

[Icy.Waffles]

Yes if your intention is to clean wipe the HDD before install OS.

Hi. I have done the following and finally all the old files are deleted. Thanks. However, when I restarted my computer, this problem came out

 

[jtjt00]

Which boot device is selected in the BIOS?

During OS setup disconnect all secondary HDD/SSD except the drive to install the OS.

 

[gamma7sg]

after finishing installing the OS, go back to bios and set back the boot device as the harddisk where the OS was installed.

Hi. I have done the following and finally all the old files are deleted. Thanks. However, when I restarted my computer, this problem came out

 

[commach]

Hi. I have done the following and finally all the old files are deleted. Thanks. However, when I restarted my computer, this problem came out

This means the Windows7 DVD is not the first boot device in the BIOS, which also explained why you got the funny issues earlier on.

If you have problem navigating the BIOS for the first boot device option, spam F8 with the DVD in the optical drive during initial boot. It will proceed to boot up with the Asus's boot menu, you can select the optical drive as the boot up device and proceed to install Windows 7.