Please HELP: Windows 7 manually repairing windows bootloader commands

I have downloaded Windows7 recovery CD and now try to Manually Repairing the Windows Bootloader by typing the command:

bootrec.exe /fixmbr

But then I receive the following error message:

sh: bootrec.exe: command not found

Please advice what to do and how to use the recovery CD

Can somebody give advice which commands to type when using the manual repair option. Clearly it does not recongnise DOS commands. And the commands given in the instructions provided on the neosmart website don't work.

Any help will be appreciated.