Visual Studio 2008: x64 Debugger error

Got the error below when tried to run the VS2K8 in debug mode:

Error while trying to run project: Unable to start debugging.
The components for the 64-bit debugger are not registered. Please repair Visual Studio 2008 Remote Debugger installation via ‘Add or Remove Programs’ in control panel.

Install the 64-bit Remote Debugger from the following location in the installation disc:
\Remote Debugger\x64\