What Wilhelmus means is that two files autoexec.nt and config.nt are configuration files, which some programs modify when they install something on your machine. Sometimes they get corrupted.
The designation C:\ is what stands for your hard drive. The \ and what follows is a subdirectory (a folder) in which files are are stored. So, C:\Windows\Repair is the name of a subdirectory under the \Windows directory on your machine that contains the two files autoexec.nt and config.nt that store the original contents of those files in case the files by exactly the same name get corrupted in the subdirectory System32 in the \Windows directory.
Rather than repairing the files in the System32 subdirectory, Wilhelmus is telling you just to copy these files from the Repair folder to the System32 folder. You can use Windows Explorer to do this or you can do it from a command prompt.
To do so from the command Prompt just type:
copy C:\Windows\Repair\autoexec.nt C:\Windows\System32 (Then hit Enter)
Do the same for config.nt:
copy C:\Windows\Repair\config.nt C:\Windows\System32 (Then hit Enter)