Restore default security permissions for the hard disk partitions

[Guest]

Hello,
I have changed the permissions for the access of files and folders in the security tab of given in the properties of the Hard Disk Partition.Now I other users of the same computer cannot access the drive or make changes there. I tried hard to solve the problem but the output is "Access Denied". Any way to make this permissions to its default(or The normal state which it was).
My OS is Windows 7 Ultimate x64

 

[aaaa11111]

If you lost some kind of rights yourself first unlock hidden admin account
Run cmd.exe as administrator and type in "Net user administrator /active:yes"

Log into that account.
Take ownership of the lost partition
Propreties ->advanced->owner->edit->click on administrator->check replace to subcontainers->apply

fix Permissions for user or group of users
Propreties->advanced->Change permission->add user or group->set permisions->check replace all child object permission

Done

Relog to your original account
in cmd type Net user administrator /active:no