Yes, you can run multiple cTrader trading platforms at the same time on the same PC.
To do that, you just need to install multiple cTrader trading platforms to your PC.
To install multiple platforms, please choose different folders to install into. Otherwise, second platform can rewrite the data of the first one and there will remain only one platform.
Alternatively, you can sign in to multiple cTrader accounts on the same trading platform and switch accounts within there.