`n
is a line feed character. Notepad (prior to Windows 10) expects linebreaks to be encoded as `r`n
(carriage return + line feed, CR-LF). Open the file in some useful editor (SciTE, Notepad++, UltraEdit-32, Vim, ...) and convert the linebreaks to CR-LF. Or use PowerShell:
(Get-Content $logpath | Out-String) -replace "`n", "`r`n" | Out-File $logpath