hope you watched video posted by Joshi bro and havnt missed any step in configuration.
also hope that you followed some steps suggested by us those are practical solutions to some problems)
also hope that you visited related thread
no harm in reinstalling all 3, Amibroker, NestTrader and RTD,
start with reinstalling RTD first, check.
if not working then RTD and NestTrader and check
but do it at your own risk, and not because we said so.
No need to format C drive. Hope you have installed these 3 in C drive and not in ProgramFiles. If in C drive, then you simply delete folder and also clear Recycle bin. If in ProgramFiles, then DO NOT delete folder, you have to use control panel, to uninstall it.