C:\ is not accessible. Access is denied.

Yesterday, I got a problem about my laptop. My disk C is not accessible. So, I cannot access all files in disk C because all access is denied. I use windows 7 operating system. If you get a same problem with me, maybe it can help you. I got this solution from here. This worked to me.

1. Run computer in safe mode with command prompt by tapping F8 when your computer boot up.
2. Logon to your user account (with admin rights)
3. Type net user administrator /active:yes
4. Press Ctrl + Alt + Delete then logoff
5. Logon as administrator
6. Press Ctrl + Alt + Delete the Start Task Manager
7. Disable UAC with RegEdit by
Type regedit
Navigate to the following registry key:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\System
Locate the following REG_DWORD value:
EnableLUA
Set the value of EnableLUA to 0.
OPtional step to suppress UAC consent prompt dialog, locate the following REG_DWORD value:
ConsentPromptBehaviorAdmin
Set the value of ConsentPromptBehaviorAdmin to 0 (optional).
Exit from Registry Editor and restart the computer to turn off UAC

8. Reboot computer
9. Go to My Computer, right click C: drive, then properties, security, advanced, effective permission, select enter your own user name, OK.
Done, you have access to C: now. But must do the following to increase security because you just compromise your own computer security in this way.

10. Enable back your UAC
press windows button + R (Run)
type in msconfig
goto tools, change UAC Setting, launch, set to default
Reboot, done

Hope helpfully.. Cheers