Find your VM .pvm file right-click on it and select Open With > Parallels Mounter (or similar wording), it will mount the volume on your desktop.
The correct procedure for dealing with system files corruption is using the Windows installation media and running Recovery Console and/or Repair Install. For more information on this consult Microsoft's documentation.
I advise against replacing the file, more than likely the file is NOT corrupted, you should run chkdsk via the Recovery Console, and use Windows own tools to deal with Windows system files.
Also, be aware, that there you'll find many .dlls (and other files) in your system folders that have the same name, these are different versions of the file that got upgraded. Replacing a system file should be done using the exact same version of the file being replaced.
Last edited: Jan 15, 2012