"c:\is not accessible" from safe mode it is no problem

From the start menu, all programs is empty, I tried to click drive C from MY Computer, but came this "C:\ is not accessible. ...because it is being used by another process"

I run the 'safe mode' of windows (F8), I can see all the folders, file and programs from drive C, but from normal windows start I can not see anything.

I tried to scan for viruses using Kaspersky, but the drive C have nothing (folders or files) at all.

I installed spyware doctor, no threads.

I tried to run start--->setting--->control panel--->add&remove program,
this came out :

"windows cannot access the specified devices, path, or files. You may not have the appropriate permissions to access the item"

The system Restore status is turned off, so I cannot use the system restore.

Please help me...