Tortoise HG Error

Please help me about this error!!!It began after I have used disk clean up.

{{{
#!python

• • Mercurial version (1.8.4). TortoiseHg version (2.0.5)
    
  • Command:
    
  • CWD: C:\Windows\system32
    
  • Extensions loaded: fixfrozenexts
    
  • Python version: 2.6.6 (r266:84297, Aug 24 2010, 18:46:32) [MSC v.1500 32 bit (Intel)]
    
  • Windows version: (6, 1, 7600, 2, ''
    
  • Processor architecture: x86
    
  • Qt-4.7.1 PyQt-4.8.3
    Traceback (most recent call last):
    File "tortoisehg\hgqt\run.pyo", line 56, in dispatch
    File "tortoisehg\hgqt\run.pyo", line 229, in _runcatch
    File "tortoisehg\hgqt\run.pyo", line 302, in runcommand
    File "tortoisehg\hgqt\run.pyo", line 353, in _runcommand
    File "tortoisehg\hgqt\run.pyo", line 307, in checkargs
    File "tortoisehg\hgqt\run.pyo", line 301, in <lambda>
    File "mercurial\util.pyo", line 433, in check
    File "tortoisehg\hgqt\run.pyo", line 674, in log
    File "tortoisehg\hgqt\run.pyo", line 445, in call
    File "tortoisehg\hgqt\run.pyo", line 92, in portable_fork
    File "subprocess.pyo", line 623, in init
    File "subprocess.pyo", line 833, in _execute_child
    WindowsError: [Error 2] The system cannot find the file specified