windows cannot find c:\Windows\regedit.exe

Previous time my PC infected with virus.
Now virus be cleaned by Symantec Antivirus. But i still cannot open “Registry”.
When I try to open “Registry” by Start->Run->regedit, an error message display “windows cannot find c:\windows\regedit.exe. Make sure you typed the name correctly, and then try again. To search for a file, click Start button and click Search”.
open regedit.exe in c:\windows folder and Command Propmt is the same problem.
Repairing OS and “Sfc /Scannow” command cannot solve the problem.
Please help me open registry?