Imagine you have some sneaky spyware on your PC that makes a screenshot every 10 seconds and sends it to the attacker. The moment you create a wallet and write down your 12 secret words, he has them too. Now he only has to wait until there's big money in the wallet aaaaaand it's gone.
The thing is, you can hardly be 100 % sure that your PC is not compromised.
Unless you are mentally retarded and have near zero IQ score, otherwise I'm pretty sure that you could know easily if you were infected mate.
Since most people use windows, don't you know how to use the event logs, event viewer? if you want to see how safe are Bitcoin addresses just
Go and take a look at
directory.io there you can have access to all the private keys, just remember every page you open it saves the
Data(keys+addresses)on your hard drive and you might need to have a hard drive with the size of the moon literally to store all of them to check
Later for addresses with big amounts.