Hi,
Follow the steps and then check.
**a)**Click Start.
**b)**In the search box type Folder options.
**c)**Select View tab.
**d)**Under Advanced settings, click Show hidden files and folders, and then click OK.
e) Click to clear Hide protected Operating System files (Recommended)
**f)**Click Apply and OK.
Also see:
Change folder options
http://windows.microsoft.com/en-US/windows7/Change-folder-options
How do I remove the Windows.old folder?
http://windows.microsoft.com/en-US/windows7/How-do-I-remove-the-Windows-old-folder