I configured nobody can access my hard disk drive except me. So what happen if I reinstall my Windows 7? Can I still access to hard disk drive?
You would still be able to access your hard drive, however the new installation would require you to take ownership of any of the old directories not reinstalled by Windows.
FYI your method will only prevent people who log in to your current Windows from accessing the hard drives files. This would not prevent access from booting to another OS, like a Linux LiveCD. Nor would this prevent someone from accessing your files by removing the drive and connecting it to another system.