So I've tried Linux Mint for a couple of days and decide to remove it, mainly because it lacks hardware driver supports.
because I installed grub2 for dual-boot,, the first thing to do was to recover the original boot loader for Win7 (MBR).
I did the following steps to recover Win7 MBR:
(You need a Windows disk that matches your WIndows in laptop, for Windows 7 sp1 you can found here:
a. Put the Windows 7 installation disc in the DVD drive and reboot the computer.
b. Press a key when asked to (spacebar is always safe)
c. Choose your language and keyboard, and press Next.
d. Click Repair your computer.
e. Click on the operating system that you would like to "repair" and then click Next.
f. In the System Restore Options, click Command Prompt.
g. Enter following commands:
(Above steps are combined from these two pages:
Then I tried to reboot, now it can boot to Windows right away, grub2 is gone.
But there is a problem: F11 (Factory restore) button never works when booting the laptop.
I guess that's because I rewrite MBR from Win7 disk and it's different from what was in my laptop before I did dualboot.
Unfortunately, I haven't found a way to re-enable the F11 function yet.